User talk:Hoskir

From Engineering Policy Guide
Revision as of 15:50, 26 May 2026 by Hoskir (talk | contribs) (→‎REVISION REQUEST 4213)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

REVISION REQUEST 3763 (ON HOLD)

REVISION REQUEST 3818 (ON HOLD)

REVISION REQUEST 3902 (ON HOLD)

REVISION REQUEST 3905 (ON HOLD)

REVISION REQUEST 3906 (ON HOLD)

REVISION REQUEST 3934 (ON HOLD)

REVISION REQUEST 4014 (ON HOLD)

REVISION REQUEST 4036 (ON HOLD)

REVISION REQUEST 4136 (ON HOLD)

REVISION REQUEST 4165

Several foundational documents guide MoDOT’s TSMO program:

  • TSMO Program and Action Plan – outlines MoDOT’s statewide TSMO vision, goals, and implementation strategies.
  • TSMO Informational Memoranda – provides background, technical details, and
  • TSMO Benefit-Cost Reference Memo – provides the benefit-cost information on TSMO applications that are critical to MoDOT’s TSMO program and future work.
  • Work Zone Management Guidebook – provides a comprehensive set of tools and strategies for work zone management and describes “advanced work zone” practices, guidance, and resources
  • Connected and Automated Vehicle Action Plan – articulates MoDOT’s mission, vision, strengths, and strategic focus areas for leveraging CV/AV technologies, and lays out actions across institutional capability-building, outreach and education, and partnership development to support safe, efficient deployment.

Transportation Systems Management and Operations (TSMO) consists of operational strategies and systems that cost-effectively optimize the safety, reliability, efficiency, and capacity of the transportation system. TSMO emphasizes maximizing the performance of the existing system through proactive management and operational improvements.

909.1 Introduction to TSMO

909.1.1 Overview of TSMO Strategies

TSMO strategies are the day-to-day operational actions MoDOT uses to actively manage the transportation system and address the primary causes of congestion without relying solely on capacity expansion.

Congestion generally falls into two categories:

  • Non-recurring delays arise from unplanned or irregular events such as incidents, disasters, weather, work zones, and special events. These disruptions are inherently unpredictable, vary in severity and duration, and often require dynamic traffic management and interagency coordination to reduce their impact.
  • Recurring delays occur regularly at specific locations, most often during peak traffic periods. This type of congestion is usually the result of demand exceeding the capacity of the existing system. Transportation agencies do not have the resources to construct enough highway capacity to eliminate all recurring congestion. Instead, TSMO strategies provide more cost-effective ways to manage demand and improve flow.

By addressing both types of congestion, TSMO supports MoDOT’s mission of moving Missourians safely and reliably while making the best use of available resources. These strategies are organized based on whether they address non-recurring delays or recurring delays, as described below.

909.2 Non-Congested Route (Non-Recurring Delays) – These strategies focus on managing temporary (whether short-term or long-term) capacity reductions caused by irregular or time-limited events that disrupt normal traffic conditions, with the goal of restoring mobility and safety efficiently and consistently.

  • 909.2.1 Traffic Incident Management: Coordinates detection, response, and clearance across multiple agencies to minimize secondary crashes and return roadways to normal operation quickly.
  • 909.2.2 Transportation Operations for Emergency Incidents or Disasters: Supports system readiness and coordinated response during natural or human-caused disasters through planning, communication, and multimodal evacuation procedures.
  • 909.2.3 Road Weather Management: Integrates environmental monitoring, data-driven decision support, and targeted maintenance to mitigate the effects of adverse weather on safety and mobility.
  • 909.2.4 Work Zone Traffic Management: Applies smart work zone technologies and comprehensive traffic management plans to maintain safe and reliable travel through construction and maintenance areas.
  • 909.2.5 Planned Special Event Management: Coordinates transportation, enforcement, and communication activities for scheduled events to maintain efficient system operations and traveler safety.

909.3 Congested Route (Recurring Delays) – These strategies address predictable and routine congestion caused by daily travel demand and capacity constraints on specific facilities or corridors, emphasizing active traffic management, system integration, and multimodal coordination.

  • 909.3.1 Freeway Operations and Management: Improves freeway performance through corridor-level monitoring, adaptive control, and coordinated operations to enhance safety and travel-time reliability.
  • 909.3.2 Arterial Operations and Management: Optimizes signal timing, intersection design, and corridor coordination to improve mobility and safety on surface streets.
  • 909.3.3 Freight Operation: Enhances the efficiency and safety of freight movement through improved access, parking management, and technology-based monitoring along key freight corridors.
  • 909.3.4 Vulnerable Road Users: Improves safety, accessibility, and comfort for VRUs through targeted infrastructure, operational strategies, and multimodal coordination.
  • 909.3.5 Transit Operation: Strengthens transit reliability and accessibility through operational strategies such as priority treatments, multimodal hubs, and corridor management.

909.1.2 Relationship with Other Programs

TSMO is not a standalone initiative—it complements and enhances MoDOT’s other programs:

  • Safety Programs: TSMO contributes to MoDOT’s safety goals, as outlined in the Strategic Highway Safety Plan and the SAFER Program (see EPG 907.9 Safety Assessment For Every Roadway (SAFER)), by reducing secondary crashes, improving work zone management, and advancing road weather management capabilities.
  • Asset Management: Proper maintenance of TSMO strategies and supporting systems can improve how facilities operate, reduce incidents that accelerate wear, and extend the life of infrastructure investments.
  • Planning and Design: TSMO principles should be incorporated early in the planning and design process so that operational strategies are built into projects from the start.
  • Maintenance: Maintenance activities can be coordinated with TSMO tools such as smart work zones and ITS devices to reduce traffic disruptions.
  • Traveler Information: TSMO strengthens customer service by providing real-time, accurate, and actionable information to the traveling public.

In practice, TSMO serves as the operational thread that connects safety, planning, design, maintenance, and customer service into a unified system-management approach.

909.1.3 Roles and Contributions for TSMO Implementation

This guide is designed to provide MoDOT staff and partners with a clear, practical reference for TSMO strategies. Table 909.1.3 highlights the typical roles and potential TSMO contributions of different staff in implementing and supporting TSMO strategies, as applicable based on project context, needs, and available resources. These contributions are intended to guide coordination and consideration of TSMO strategies and may vary depending on the specific application.

Table 909.1.3. Typical Roles and Potential Contributions for TSMO Implementation
Role Potential TSMO Contribution
Transportation Management Center (TMC) Operator Monitor traffic conditions, manage information systems, and coordinate incident response and traveler communication to maintain safe and efficient roadway operations.
Emergency Response Operator Provide on-scene incident management, motorist assistance, and roadway clearance to restore normal traffic flow and enhance safety during disruptions.
Maintenance Technician Implement maintenance related TSMO strategies; provide feedback and effort for continual improvement of these strategies and tools.
Traffic Operations Engineer Implement traffic operations related TSMO strategies; provide feedback and effort for continual improvement of these strategies and tools.
Transportation Planner Incorporate TSMO and other traditional transportation improvement strategies into planning efforts, as appropriate.
Design Staff Consider TSMO as a key element of design, where applicable, either as a direct improvement for the specific application or as an opportunity for the continuation of existing TSMO strategies.
Construction Inspector Coordinate with appropriate personnel when modifying design elements or inspecting TSMO related infrastructure.
Work Zone Specialists Oversee temporary traffic control in construction zones; review and manage Transportation Management Plans (TMPs), ensure proper setup and quality of traffic control devices, assess risks, and provide input during planning and post-construction reviews to enhance safety and minimize disruptions.
Information Systems Manager Provide oversight and management of field and central communications systems, computer and software, and other information systems resources.
Human Resources Specialist Incorporate relevant related skills and experience into position descriptions where TSMO expertise is needed; assist with training programs to improve the knowledge, skills, and abilities of existing operations personnel.
Emergency Management Agencies Support TSMO implementation by providing coordinated incident response, traffic control, emergency medical services, and roadway clearance; collaborate with MoDOT and TMC staff, when applicable, to improve incident management, responder safety, and system recovery during emergencies and planned events.

909.1.4 TSMO Implementation Framework

The TSMO Implementation Framework provides a structured approach for MoDOT to translate its mission and agency goals into actionable objectives and strategies. It supports the development of purpose-driven, measurable strategies aligned with statewide priorities. This framework serves as a bridge between MoDOT’s overarching mission and the specific strategies implemented across the TSMO program. Effective implementation of these goals relies on coordination across disciplines, integration throughout project phases, and collaboration with internal and external partners.

Table 909.1.4.1 identifies the core programmatic elements, MoDOT’s goals and associated objectives, that guide how TSMO is planned, implemented, and evaluated.

Table 909.1.4.1 Programmatic Element
Goal Objective
Safety Reduce crash frequency and severity through proactive deployment of TSMO strategies (e.g., incident management, work zone safety, network operations).
Reliability Support predictable and consistent travel times across the system by proactively managing congestion and incidents.
Efficiency Operate MoDOT’s existing system efficiently and effectively through the application of TSMO strategies, as appropriate, to improve performance and inform decisions regarding potential capacity expansion.
Customer Service Support timely, accurate, and useful traveler information that enables informed decision-making.

Table 909.1.4.2 links MoDOT’s mission to measurable outcomes and example TSMO strategies, demonstrating how operations initiatives directly support statewide goals.

Table 909.1.4.2. Linking MoDOT Mission to Outcomes and Example TSMO Strategies
Mission High-Level Outcome Example TSMO Strategy
Improving safety (Moving Missourians safely) Reduction in crashes, fatalities, and serious injuries; safer travel for all users • 909.2.1 Traffic Incident Management
• 909.2.3 Road Weather Management
• 909.2.4 Work Zone Traffic Management
• 909.3.1 Freeway Operations and Management
• 909.3.2 Arterial Operations and Management
Providing high-value, impactful solutions (Delivering efficient and innovative transportation projects; asset management) Cost-effective improvements that maximize existing infrastructure and delay costly expansions • 909.3.1 Freeway Operations and Management
• 909.3.2 Arterial Operations and Management
• 909.3.3 Freight Operation
• 909.3.4 Vulnerable Road Users
Improving reliability and mobility (Operating a reliable transportation system; Building a prosperous economy for all Missourians) Predictable travel times and improved system performance for people and freight • 909.2.1 Traffic Incident Management
• 909.2.4 Work Zone Traffic Management
• 909.2.5 Planned Special Event Management
• 909.3.1 Freeway Operations and Management
• 909.3.5 Transit Operation
Providing useful and timely traveler information (Providing outstanding customer service) Informed travel decisions by the public, increased user satisfaction • 909.2.2 Transportation Operations for Emergency Incidents or Disasters
• 909.2.3 Road Weather Management

909.1.5 Performance Metrics

Performance metrics provide the foundation for evaluating how TSMO strategies contribute to the safety, reliability, efficiency, and customer experience of Missouri’s transportation system. MoDOT currently tracks performance through a combination of federal performance measures and internal performance management tools (e.g. Tracker: Measures of Departmental Performance). The following tables present example performance measures that may be used to assess the effectiveness of TSMO strategies related to both non-recurring delays (Table 909.1.5.1) and recurring delays (Table 909.1.5.2).

These measures are not intended to represent required or standalone reporting metrics, but rather a menu of potential measures that can support analysis, planning, and evaluation efforts, as appropriate to the specific application, study type, or operational need. When applied, these metrics can help users identify opportunities for improvement and support data-driven decision-making.

Table 909.1.5.1 Linking MoDOT TSMO Strategies for Non-Recurring Delays to Performance Metrics
Strategy Goals Example Performance Metric
909.2.1 Traffic Incident Management Enhance the safety of traveling public and incident responders • Number of secondary crashes per incident
• Severity (fatalities/serious injuries) of secondary crashes
• Percent of incidents with secondary crashes recorded
• Number of responders struck-by crashes
• Severity of responder-involved crashes
• Percent of incidents with responder crash data recorded
Enhance reliability and efficiency of Missouri’s transportation system • Average roadway clearance time
• Average incident clearance time
• Percent of incidents meeting clearance time targets
Strengthen coordination, communication, and collaboration between MoDOT and TIM partners • Number of formalized agreements signed
• Number of multi-agency TIM meetings held annually
• Number of TIM trainings held annually
• Partner participation rate in meetings/exercises
Establish TIM policies, procedures, and protocols within MoDOT • Number of formal TIM policies/protocols adopted
• Percent of TIM coordinator positions filled and active
909.2.2 Transportation Operations for Emergency Incidents or Disasters Enhance safety and responder protection during emergency incidents • Number of emergency-related crashes
• Severity (fatal/serious injury) of emergency-related crashes
• Percent of emergency incidents with responder safety data recorded
Improve reliability and speed of emergency response and system restoration • Time to activate emergency operations
• Duration of emergency lane/road closures
• Percent of priority routes restored within target timeframes
• Emergency communication system uptime
• Average time to deploy emergency traffic control
909.2.3 Road Weather Management Improve safety under adverse weather conditions • Number of weather-related crashes, fatalities, and serious injuries
• Crash rate per weather event
Enhance operational readiness and timely roadway treatment • Time to treat priority routes during storms
• Percent of network treated within specific time thresholds
• Materials usage efficiency (salt, brine, abrasives)
Improve traveler information accuracy during weather events • Traveler information system accuracy rate during storms
• Number of travel information interactions (511 apps, CMS messages)
909.2.4 Work Zone Traffic Management Enhance safety for workers and motorists in work zones • Number and rate of work zone crashes
• Number of work zone fatalities and serious injuries
• Number of work zone intrusions (near-miss events)
Improve mobility and reduce unexpected work zone delays • Work-zone related delays
• Percent of work zones meeting mobility targets (queue length, speed, travel time)
• Average incident clearance time for work zone-related incidents
909.2.5 Planned Special Event Management Ensure safe travel conditions during special events • Number and rate of special event-related crashes
• Vulnerable Road User (VRU) level of comfort/safety index near event venues
Improve mobility and minimize event-related congestion • Travel time reliability during event periods
• Vehicle and pedestrian throughput at key access points
• Percent of events meeting planned operational performance targets


Table 909.1.5.2 Linking MoDOT TSMO Strategies for Recurring Delays to Performance Metrics
Strategy Goals Example Performance Metric
909.3.1 Freeway Operations and Management Support safety on managed freeway facilities • Number and rate of crashes on freeway segments
• Number of secondary crashes
Improve travel reliability on freeway corridors • Travel time reliability index
• Planning time index
Enhance operational efficiency on freeway corridors • Average travel speed and delay
• Vehicle and truck throughput
• Number of recurring congestion hotspots mitigated
909.3.2 Arterial Operations and Management Enhance safety at signalized intersections and arterials • Crash frequency and severity at signalized intersections
• Pedestrian and bicycle crash rate
Improve efficiency of arterial traffic flow • Arterial travel time and delay
• Signal progression quality (arrival on green, bandwidth)
• Number of mitigated congestion hotspots
Enhance reliability of multimodal arterial operations • Transit signal delay at signals (if applicable)
• Pedestrian crossing delay
909.3.3 Freight Operation Improve efficiency on key freight corridors • Truck delay at bottlenecks
• Freight throughput (corridor or intermodal facility)
Enhance reliability of freight travel • Truck travel time reliability index
• Number of freight-related congestion hotspots mitigated
909.3.4 Vulnerable Road Users Enhance safety and comfort for Vulnerable Road Users (VRUs) • Number and rate of VRU crashes
• VRU level of comfort/safety index
Improve connectivity for walking and bicycling • Miles of connected pedestrian/bicycle facilities
• Percent of network meeting connectivity standards
Support sustainable, multimodal travel options • Share of trips completed using active modes
909.3.5 Transit Operation Enhance mobility of transit users • Passenger throughput per route or corridor
• Average transit travel time
Improve transit reliability and on-time performance • Percent of on-time arrivals
• Transit travel time reliability (travel adherence)
Improve customer experience and multimodal access • Customer satisfaction survey results
• Pedestrian access quality (stop accessibility index)





909.2 Non-Congested Route (Non-Recurring Delays)

909.2.1 Traffic Incident Management

Traffic Incident Management (TIM) can help reduce the impact of roadway incidents by coordinating detection, response, and clearance activities among transportation, law enforcement, fire, EMS, towing, and other partners.

While crashes, disabled vehicles, and cargo spills are the most common focus of TIM programs, there are a broader set of disruptions that can also be monitored including:

  • Debris in the roadway
  • Grass fires
  • Lane-blocking emergency vehicles
  • Vehicle fires
  • Heavy congestion

By incorporating this broader incident set, TIM strategies ensure operators and responders are prepared for a wide range of events that may impact traveler safety and network performance. The following sections outline strategies for TIM.

Users:

909.2.1.1 Traffic Incident Management Plans

Traffic incidents occur without warning at any time and location on the highway system. On all segments of the interstate and freeway highway system, TIM plans should be developed in coordination with law enforcement and local responders to:

  • Reduce response and clearance times.
  • Develop alternate plans for handling affected traffic.
  • Communicate and coordinate between first responders.
  • Communicate traffic impacts to motorists.

Reference EPG 948 Incident Response Plan and Emergency Response Management for additional information.

909.2.1.2 Stakeholders

Effective TIM depends on collaboration among a wide range of partners. Law enforcement, fire/rescue, EMS, and towing operators provide immediate on-scene response, while MoDOT personnel and TMCs deliver critical support through detection, traffic control, and traveler information. Each stakeholder brings unique capabilities, and coordinated multi-agency response supports faster clearance, safer conditions for responders, and more reliable outcomes for the traveling public.

909.2.1.3 Components

The core components of TIM—detection, verification, response, clearance, and recovery—create a structured framework for managing roadway incidents. Detection and verification confirm the incident type and location; coordinated response mobilizes the appropriate agencies; clearance restores traffic lanes and removes hazards; and recovery ensures the roadway is returned to normal operation. Addressing each component systematically reduces incident duration and enhances both safety and reliability.

909.2.2 Transportation Operations for Emergency Incidents or Disasters

Emergency operations support safe and effective evacuation and mobility during disasters such as floods, tornadoes, earthquakes, or other emergencies. The following sections outline strategies for emergency operations during disasters.

Users:

909.2.2.1 Frameworks and Coordination

MoDOT’s emergency transportation operations should align with the National Incident Management System (NIMS) and the Incident Command System (ICS). These frameworks establish the standard structure, terminology, and coordination processes for incident and disaster response at the local, state, and federal levels.

National Incident Management System (NIMS):

  • Provides a nationwide approach for incident management and coordination.
  • Provides emergency transportation operations guidance for interoperable collaboration with law enforcement, fire, EMS, emergency management, and federal partners.
  • Establishes common terminology, communication protocols, and resource management procedures to support multi-agency operations.

Incident Command System (ICS):

  • Serves as the on-scene management structure for all types of incidents.
  • Defines clear roles, responsibilities, and reporting relationships across agencies.
  • Provides guidance on unified command structures, filling roles such as transportation branch directors, field observers, or technical specialists.
  • Provides flexibility to scale operations for localized or statewide events.

For detailed response information, please contact MoDOT’s Safety and Emergency Management.

909.2.2.2 Preparedness and Planning

  • Develop and exercise evacuation and emergency operations plans.
  • Use simulation and scenario testing to identify gaps and strengthen interagency protocols.
  • Establish pre-designated staging areas for resource allocation, evacuation support, and vehicle marshaling.

909.2.2.3 Operational Strategies During Disasters

  • Traffic Management: Complete rapid damage assessment and plan and publish routes for ingress and egress to the impacted area.
  • Multimodal Evacuations: Utilize buses, school buses, and regional transit providers to assist in large-scale evacuations.
  • Route Monitoring: Employ field observations, cameras, and sensors to track evacuation route conditions in real time.
  • Public Information: Provide timely traveler information, evacuation messaging, and updates in coordination with media partners.

909.2.3 Road Weather Management

Road Weather Management strategies improve mobility, reliability, and safety during weather events through strategies such as targeted traveler information, warnings, and operational interventions. The following sections outline strategies for road weather management.

Users:

909.2.3.1 Road Weather Warnings/Alerts and Dynamic Message Signs

Used to display real-time information to warn motorists of roadway incidents, construction or congestion ahead that could pose a hazard or cause delays.

Procedures for Dynamic Message Signs are outlined in EPG 910.3 Dynamic Message Signs (DMS).

909.2.3.2 Road Weather Information Systems

Road Weather Information Systems (RWIS) provide real-time data on weather and roadway conditions to support transportation system operations and maintenance activities. These systems collect information such as air and pavement temperatures, precipitation, visibility, and surface conditions to help inform operational decisions. Data may be collected through field sensors, third-party weather service providers, or a combination of both, depending on system needs and available resources.

909.2.4 Work Zone Traffic Management

Work zone strategies reduce risk to workers and travelers while minimizing delays during construction and maintenance activities. These strategies apply to both short-term and long-term work zones, recognizing that every project, regardless of duration, can significantly affect roadway operations and safety. The following sections outline strategies for work zone traffic management.

Users:

909.2.4.1 Traffic Management Plan

The Transportation Management Plan (TMP) consists of strategies to manage the work zone impacts of a project. Each TMP is tailored to the unique conditions of a project and typically incorporates three coordinated elements: Traffic Control Plan (TCP), Traffic Operations (TO), and Public Information and Outreach (PIO).

As an initial step, a project design should be selected to eliminate or minimize additional delays and traffic queueing during construction. EPG 616.19 Work Zone Capacity, Queue and Travel Delay provides tools to assess the traffic impact of the proposed project design(s).

For additional detail on the required elements, development process, and documentation standards for TMPs, reference EPG 616.20.9 Work Zone Transportation Management Plan. For additional information on developing Work Zone Traffic Management JSPs for use in core team meetings, reference EPG 616.20.7 Significant Projects.

909.2.4.2 Traffic Incident Management Plan

When traffic incidents occur within a work zone, it is important to clear the incident and restore traffic as quickly as possible. To aid in this effort, a project-based traffic incident management (TIM) plan should be developed for all significant projects on interstate and freeways.

Reference EPG 909.2.1.1 Traffic Incident Management (TIM) Plans for additional information.

909.2.4.3 Smart Work Zones

Once a project design has been determined, the MoDOT Work Zone Impact Analysis Spreadsheet will assist in determining which smart work zones strategies should be included in the project to provide information and warnings to motorists to improve work zone safety and traffic mobility.

Additionally, the Work Zone Management Guidebook provides information about tools and strategies for work zone management that will maximize safety and minimize the impacts to traffic. The Work Zone Management Guidebook Presentation provides additional information about the guidebook.

The nonstandard Work Zone Intelligent Transportation System special provision is available for reference in EPG 616.19.6.3 Smart Work Zone (SWZ) Strategy Selection. Additional information can also be found in EPG 616.19 Work Zone Capacity, Queue and Travel Delay and EPG 616.20 Work Zone Safety and Mobility Policy.

909.2.4.4 Use of Intelligent Transportation Systems

Intelligent Transportation Systems (ITS) devices (cameras, sensors, communication systems) provide detection and real-time monitoring of work zones.

Procedures for ITS devices are outlined in EPG 910 Intelligent Transportation Systems.

909.2.5 Planned Special Event Management

Special event management strategies ensure safe and efficient mobility during large gatherings, sporting events, and other planned activities. The following sections outline strategies for planned special event management.

Users:

909.2.5.1 Pre-Event Planning

  • Develop Transportation Management Plans (TMPs) with input from MoDOT, local agencies, law enforcement, transit providers, and event organizers.
  • Identify needs for Emergency Operations Center (EOC) and Joint Operations Center (JOC) activation, staffing augmentation, and resource staging for high-profile or large-scale events (e.g., sporting events, major concerts, parades, funerals, festivals, eclipse, political events).
  • Plan for multimodal access (transit, walking, biking) and freight restrictions, where applicable.

909.2.5.2 Implementation

  • Deploy traffic control devices, signage, and ITS in advance of the event.
  • Coordinate with law enforcement and emergency management on enforcement zones, access control, and responder staging.
  • Conduct interagency briefings to confirm roles, responsibilities, and communication protocols.

909.2.5.3 Day-of-Event Operations

  • Manage traffic and crowd circulation using TMC monitoring, field staff, and real-time traveler information (dynamic message signs, push alerts, social media).
  • Coordinate with EOC/JOC if activated to ensure situational awareness and resource support.
  • Adjust plans dynamically to address congestion, incidents, or security needs.

909.2.5.4 Post-Event Evaluation

  • Conduct after-action reviews with MoDOT staff, law enforcement, emergency management, and event organizers.
  • Document lessons learned, identify gaps in staffing or coordination, and refine TMPs for future events.
  • Capture performance measures such as clearance times, delay estimates, and traveler feedback.





909.3 Congested Route (Recurring Delays)

909.3.1 Freeway Operations and Management

Freeway operations strategies help enhance safety, reduce recurring congestion, and improve travel time reliability on major corridors. The following sections outline some strategies for freeway operations and management. Not all strategies discussed below are currently used in Missouri; however, they are included to provide a range of options that may be considered based on context, needs, and available resources.

Users:


Policy Coordination – It is encouraged that any consideration or application of the following strategies should be closely coordinated with applicable Central Office staff, including the Highway Safety and Traffic Division, as well as other related divisions to support consistency with MoDOT policy, design standards, and operational practices.

909.3.1.1 Ramp Management and Control

Ramp management and control strategies, including ramp metering and adaptive ramp management, regulate vehicle entry onto freeways to improve merging operations, reduce conflicts, and smooth overall traffic flow. This remains a dynamic application where it is implemented, with operational adjustments based on corridor conditions.

Currently, Missouri does not operate continuous ramp metering systems. Instead, ramp meters are activated dynamically based on real-time traffic conditions when metrics (such as speed, volume, and/or density) exceed predefined thresholds.

909.3.1.2 Part-Time Shoulder Use (Hard Shoulder Running)

Part-time shoulder use, also known as hard shoulder running, allows roadway shoulders to serve as temporary travel lanes during peak periods, incidents, or emergencies. Applications may be designed for all vehicles or limited to transit operations.

This strategy is increasingly being implemented by peer agencies across the country, particularly in corridors with limited right-of-way or peak-period capacity needs. While Missouri does not currently have any active applications of part-time shoulder use, the concept may present opportunities in select corridors - especially where traditional widening is not feasible and where shoulders are constructed to full-depth pavement standards.

909.3.1.3 Dynamic Speed Limits

Dynamic speed limits adjust posted speed limits in real time based on conditions such as traffic flow, weather, or incidents. This approach has been applied by several peer agencies to improve safety, smooth traffic flow, and reduce crash risk.

In Missouri, there are no permanent applications of dynamic speed limits in routine freeway operations. However, the strategy may hold value in temporary, controlled environments, particularly in work zones, where changing conditions may warrant more flexible speed management.

909.3.1.4 Queue Warning

Queue warning systems are designed to alert motorists of slow or stopped traffic ahead, helping to reduce the likelihood of sudden braking and rear-end collisions. In Missouri, queue warning is typically implemented using probe data to identify travel times, including delays associated with downstream incidents or congestion, and to display warning messages on Dynamic Message Signs (DMS).

In work zones, queue warning applications commonly include the use of probe data linked to DMS, as well as sensor-based systems that detect traffic conditions and trigger messages on Changeable Message Signs (CMS). These approaches help provide advance warning to drivers when queues form due to temporary capacity constraints and changing traffic conditions.

Effective implementation requires appropriate placement of signs upstream of anticipated queue locations and consideration of roadway speeds to ensure adequate driver perception and reaction time.

909.3.1.5 Transportation Management Centers

Transportation Management Centers (TMCs) serve as the operational backbone of ICM. From TMCs, MoDOT staff monitor real-time traffic conditions, manage ITS devices, coordinate incident response, and adjust strategies such as ramp metering or queue warning. This centralized approach enables proactive management of corridors, supporting safety and reliability during incidents, work zones, and peak travel periods.

909.3.1.6 Managed Lanes

Managed lanes are roadway segments where access and use are actively regulated to improve traffic flow, safety, or reliability. Common approaches used nationally include bus-only lanes and truck-only lanes. These treatments are typically considered in locations with recurring congestion, limited right-of-way, or freight movement challenges.

At present, Missouri has no active managed lane facilities.

909.3.1.7 Automated Incident Detection

Automated incident detection systems use roadside sensors, video feeds, and software algorithms to identify crashes, stalled vehicles, or other disruptions in real time. These systems often integrate data analytics with CCTV camera footage to detect unusual traffic patterns or stopped vehicles more quickly than traditional operator observation alone. By providing earlier notification of likely incidents, automated detection enhances safety, reduces secondary crashes, and improves response times for emergency and traffic management personnel.

909.3.2 Arterial Operations and Management

Arterial operations strategies help improve mobility, safety, and reliability on surface streets through targeted improvements, signal operations, and multimodal accommodations. These strategies focus on reducing congestion at bottlenecks, enhancing intersection performance, and supporting consistent travel across urban and suburban corridors.

In Missouri, arterial management is often a shared responsibility between MoDOT and regional or local partners. For example, the Kansas City region’s Operation Green Light program coordinates arterial signal timing and corridor operations in collaboration with MoDOT and multiple local jurisdictions. Other examples include MoDOT’s partnership with St. Charles in the St. Louis region and collaboration with the City of Springfield and the Ozarks Transportation Organization. Similar arrangements may exist in other regions where MPOs, cities, or counties lead day-to-day arterial management. Practitioners should recognize that depending on the corridor and location, responsibility for arterial operations may rest with another entity, requiring coordination and partnership to ensure consistent system performance.

The following sections outline strategies for arterial operations and management.

Users:


Policy Coordination – It is encouraged that any consideration or application of the following strategies should be closely coordinated with applicable Central Office staff, including the Highway Safety and Traffic Division, as well as other related divisions to support consistency with MoDOT policy, design standards, and operational practices.

909.3.2.1 Targeted Infrastructure Improvements

Targeted infrastructure improvements are localized enhancements that address recurring bottlenecks or multimodal safety concerns on arterial corridors. Common treatments include new or extended turn lanes to reduce delay at intersections, access control to improve traffic flow and safety, and bus pullouts to minimize transit-related delays. Pedestrian and bicyclist accommodations such as crosswalk improvements, refuge islands, and protected lanes also support safer and more reliable mobility for all users.

909.3.2.2 Alternative Intersection Designs

Alternative intersection designs apply alternative layouts to improve safety and efficiency where traditional designs are constrained. Examples include restricted crossing U-turns (RCUTs), median U-turns, and displaced left-turn (continuous flow) intersections, which reduce conflict points and increase throughput. These designs are increasingly considered where right-of-way is limited, traffic volumes are high, or safety issues persist with conventional layouts.

Additional information can be found in EPG 233.5 Intersection Alternatives.

909.3.2.3 Traffic Signal Program Management

A comprehensive traffic signal program helps support effective corridor operations. Program elements include monitoring and evaluating existing signal systems, scheduling recurring retiming efforts, and integrating new technologies over time. A proactive, programmatic approach supports consistent signal management across jurisdictions, improving reliability and reducing the need for inefficient, piecemeal adjustments.

Procedures for signal operation and maintenance are outlined in 902.1.10 Responsibility for Operation and Maintenance (MUTCD Section 4A.10).

909.3.2.4 Traffic Signal Timing and Coordination

Traffic signal timing and coordination strategies are a cost-effective approach to improve arterial operations. By updating signal timing plans and coordinating operations across intersections, agencies can reduce delays and support more predictable travel along corridors. These strategies allow signal operations to reflect current traffic conditions, land use patterns, and system changes, while also providing a foundation for integrating advanced technologies such as adaptive control.

Applications:

  • Traffic Signal Retiming – Updating the timing plans for one signalized intersection or a corridor of intersections based on the latest traffic volumes. Retiming is recommended every few years or after significant changes to transportation systems or land use within a given area.
  • Traffic Signal Coordination – Coordinating traffic signal timing along a corridor to enable a “green wave” of vehicles traveling through a sequence of signals. Coordination optimizes the splits and offsets of signals to allow for smoother, progressive traffic flow.
  • Adaptive Traffic Signal Control – Coordinating traffic signal timing across a network using real-time detector data to accommodate current, prevailing traffic patterns. This allows for dynamic adjustment of timing in response to fluctuating traffic conditions.

Procedures for signal phasing and operation are outlined in EPG 902.23 Traffic Signal Phasing and Operation.

909.3.2.5 Transit Signal Priority

Transit signal priority (TSP) strategies adjust signal phasing to reduce delay for buses and improve the efficiency of transit operations. TSP can extend green phases and/or provide early green intervals to help transit vehicles move more consistently through intersections. By enhancing the speed and reliability of bus service, TSP supports multimodal goals and encourages greater use of transit along arterial corridors.

909.3.2.6 Arterial Dynamic Shoulder Use

Arterial dynamic shoulder use provides additional capacity and helps improve multimodal efficiency by repurposing existing roadway space under defined conditions. Dynamic shoulder use allows roadway shoulders to operate as travel lanes during peak periods or special events, while maintaining their primary role for emergency access during off-peak times. When feasible, this strategy can help reduce delays, improve vehicle-throughput, and support multimodal goals in areas where right-of-way is constrained and traditional widening is not feasible. Successful implementation requires clear operational policies, appropriate signing and striping, and coordination with enforcement and transit partners to ensure safety and effectiveness.

Although Missouri does not currently implement arterial dynamic shoulder use, the approach may offer targeted benefits in select corridors. However, because shoulders are typically not constructed to full-depth pavement standards, implementation would likely require reconstruction or significant upgrades to support sustained traffic loading.

909.3.3 Freight Operation

Freight operations strategies address truck mobility, parking, and safety near freight generators such as ports and distribution centers. The following sections outline key strategies for freight operations.

Users:

Reference MoDOT’s 2022 State Freight and Rail Plan Documents for additional information.

909.3.3.1 Freight Operations Around Ports and Generators

Freight hubs such as ports, intermodal yards, and distribution centers generate concentrated truck activity that can create localized congestion and safety concerns. Targeted operational improvements may include intersection upgrades, dedicated freight lanes, improved signage, or optimized signal timing along key freight corridors. These measures reduce bottlenecks, improve travel time reliability for trucks, and minimize conflicts between freight and passenger vehicles in high-demand areas.

909.3.3.2 Truck Parking

Adequate truck parking supports driver safety, freight efficiency, and regulatory compliance. Strategies include the development of new truck parking facilities, upgrades to existing rest areas, and the integration of real-time availability systems that help drivers locate spaces. Reservation tools and wayfinding applications can further support efficient parking use and reduce the safety risks associated with unauthorized shoulder or ramp parking.

909.3.3.3 Regional Permitting

Freight often crosses multiple jurisdictions, and inconsistent permitting processes can add delay and administrative burden. Regional permitting strategies streamline requirements by coordinating across state, county, and local agencies. Harmonizing size, weight, and routing approvals enhances efficiency for carriers while reducing redundant processes for agencies, particularly along high-volume freight corridors.

909.3.3.4 Technology Applications for Freight

Technology provides powerful tools for managing freight mobility. Examples include routing platforms that help drivers avoid weight-restricted bridges or low-clearance structures, monitoring systems that track freight movement in real time, and automated clearance technologies at weigh stations or ports of entry. Collectively, these applications enhance efficiency, improve safety, and provide data to better manage freight corridors.

909.3.3.5 Connected and Automated Freight Vehicles

The freight industry is a leading sector for testing and deploying connected and automated vehicle (CV/AV) technologies. Applications may include platooning, automated truck-mounted attenuators, or fully automated long-haul freight operations. These technologies have the potential to improve safety, reduce driver fatigue, and increase efficiency in freight corridors. Early deployment efforts require coordination with industry, agencies, and technology providers to ensure infrastructure readiness and to evaluate operational impacts.

909.3.4 Vulnerable Road Users

Vulnerable road users (VRUs) are individuals who travel without the protection of an enclosed vehicle and therefore face a greater risk of serious injury in a collision. VRUs include pedestrians, roadway workers, individuals using wheelchairs or other personal mobility devices, bicyclists, motorcyclists, and users of electric scooters and other micromobility devices. The following sections outline strategies to improve safety, access, and comfort for these users within the transportation system.

Users:

909.3.4.1 Safety Enhancements

Selective deployment of safety enhancements should be informed by EPG 907 Traffic Safety and tailored to the needs of VRUs. Enhancements may include improved crossings, lighting, signing and pavement markings, speed management strategies, traffic calming measures, work zone protections for roadway workers, and design treatments that reduce conflicts involving motorcyclists and micromobility users.

909.3.4.2 Pedestrian and Accessibility Facilities

Sidewalks, shared-use paths, accessible curb ramps, transit stop connections and enhanced or grade-separated crossings should be prioritized where safety risks, accessibility needs, or network gaps are identified. Integrating these facilities in alignment with Complete Streets principles (EPG 907.10 Complete Streets), in coordination with regional and local partners, helps support safe, efficient access for pedestrians and individuals using wheelchairs or other mobility devices.

Additional information can be found in EPG 642 Pedestrian Facilities.

909.3.4.3 Bicycle Lanes and Cycle Tracks

Where conditions and community priorities warrant, dedicated bike lanes or protected cycle tracks can enhance comfort and safety for bicyclists and other micromobility users, including users of electric scooters and similar devices. MoDOT supports the Complete Street concept (as outlined in EPG 907.10 Complete Streets) and encourages coordination with communities and regional partners to consider these facilities where appropriate.

Additional information can be found in EPG 641 Bicycle Facilities.

909.3.4.4 VRU Education and Outreach

Support community-informed education and outreach programs that promote safe behaviors among VRUs. Programs may address the needs of pedestrians, bicyclists, micromobility users, motorcyclists, individuals with disabilities, and drivers, and may include collaboration with local schools, community organizations, advocacy groups, employers, transit agencies, and public safety partners.

909.3.5 Transit Operation

Transit operations strategies improve speed, reliability, and accessibility of transit services. The following sections outline strategies for transit operations.

Users:

909.3.5.1 Transit Signal Priority

Transit Signal Priority (TSP) strategies modify traffic signal operations to reduce delay and improve on-time arrivals for buses and other transit vehicles.

Additional information on TSP is provided in EPG 909.3.2.5 Transit Signal Priority.

909.3.5.2 Bus Rapid Transit

Bus Rapid Transit (BRT) incorporates a combination of dedicated lanes, intersection treatments, and enhanced stations to provide faster and more reliable bus service. Treatments such as queue jump lanes and high-capacity vehicles further enhance performance. BRT can serve as a cost-effective alternative to rail in high-demand corridors, delivering rapid, frequent, and reliable service with improved passenger amenities.

909.3.5.3 Transit-Only Lanes

Transit-only lanes provide additional capacity and improve multimodal efficiency by repurposing existing roadway space under defined conditions. Transit-only lanes dedicate roadway space to buses, enabling more reliable service and improving schedule adherence in congested corridors. This strategy can help reduce delays, improve person-throughput, and support multimodal goals in areas where right-of-way is constrained and traditional widening is not feasible. Successful implementation requires clear operational policies, appropriate signing and striping, and coordination with enforcement and transit partners to ensure safety and effectiveness.

This strategy may offer targeted benefits in select corridors where transit demand and roadway conditions support dedicated space for transit operations. In some cases, implementation could involve repurposing shoulder space where available. However, because shoulders are typically not constructed to full-depth pavement standards, such applications would likely require reconstruction or significant upgrades to support sustained transit operations.

Policy Coordination – It is encouraged that any consideration or application of the following strategies should be closely coordinated with applicable Central Office staff, including the Highway Safety and Traffic Division, as well as other related divisions to support consistency with MoDOT policy, design standards, and operational practices.

909.3.5.4 Transit Operation Vehicles

Transit vehicle operations may require unique roadway considerations. Streetcars, for example, share corridors with general traffic and necessitate signal coordination and geometric design adjustments for turning movements. Similarly, buses may require accommodations such as bus pullouts, curb extensions, or boarding islands to improve efficiency and passenger safety. These vehicle-specific considerations support smoother operations and minimize conflicts with other modes.

909.3.5.5 Multimodal Transportation Centers

Multimodal transportation centers serve as hubs that integrate multiple travel modes, including bus, rail, bike, and pedestrian connections. These facilities improve regional accessibility by consolidating transfers in a single location and providing amenities such as shelters, ticketing, and real-time traveler information.

In Missouri, existing park-and-ride facilities present opportunities to serve as future multimodal centers. These centers encourage greater transit use, strengthen first- and last-mile connections, and elevate the role of transit in supporting regional mobility.

REVISION REQUEST 4175 (ON HOLD)

321.2.1.2 Types of Reports

1. The soil survey report touches on foundations by pointing out possible foundation problems. It also contains basic slope recommendations which affect bridge length, soil types and properties for pavement design, depths to rock and type of rock for determining cut quantities, and cut slope recommendations for soil and rock.

2. The preliminary bridge foundation report, which is submitted by the district as an adjunct to the soil survey report, is usually furnished to the Bridge Unit for their guidance in preparing preliminary bridge layouts and to the Materials Engineering Unit for guidance in conducting a more detailed foundation investigation. (Preliminary borings for such reports may be omitted where access problems are especially difficult.)

3. The final foundation investigation report will provide the requested properties from Form A of the Bridge Division Request for Soil Properties in accordance with EPG Sections 320, 321, 700 and other applicable sections. The report will also provide seismic properties as requested on Form B. The Bridge Division or District will provide the preliminary structure layout and location of each foundation location. The Geotechnical Section will determine boring locations and sampling frequency based on guidance in, EPG 321.2 Geotechnical Guidelines, and specific site conditions. The Geotechnical Section may make recommendations for specific foundation types if site conditions require special considerations. The intent is to provide the Bridge Division or District with the information needed to develop designs for the foundation types practical for a particular site. Rules of thumb as to what is practical have been developed jointly by the Geotechnical Section and the Bridge Division. These are discussed in the applicable sections within the EPG.





701 Drilled Shafts

Substructure foundations may be designed to transmit loads to foundation strata by concrete columns cast in drilled holes. See EPG 751.37 Drilled Shafts for design guidance and additional information.

This type of foundation is identified in Sec 701 of the Standard Specifications as Drilled Shafts. A drilled shaft is generally considered a deep foundation.

Drilled shafts for bridge structures:

Drilled shafts for bridge structures shall be constructed with a permanent casing and rock socketed. Requirements for plan reporting of steel casing are given in EPG 751.37.1.3 Casing.

The shaft portion of a drilled shaft is founded on rock (limestone, dolomite or other suitable material with qu ≥ 100 ksf) or weak rock (shale or other suitable material with 5 ksf ≤ qu ≤ 100 ksf) with a smaller diameter rock socket drilled into same. The inspector should carefully study all general specifications and special provisions pertaining to drilled shafts and become familiar with the designer's intent.

The integrity of the rock socket shall be verified by a foundation inspection hole. This is usually performed after the shaft is drilled. Setting up over a drilled hole can be difficult. The contractor can perform the inspection hole in advance if they submit a procedure that assures the correct location is cored. If the integrity of the cores are questionable the Bridge Division should be contacted to see if the rock socket length should be extended.

Most problems with drilled shafts occur during the concrete pour. The concrete placement requirements in Sec 701 should be reviewed carefully.

An anomaly may be detected on a Cross Hole Sonic log test. If, on further investigation, there is a confirmed defect what are some of the steps needed to remediate the defect?

1. The contractor is responsible for submitting a remediation plan for the repair.
2. The plan should include as a minimum the following:
a) The area of deficient material must be clearly defined using coring or other means.
b) The clean-out process is typically accomplished by flushing the weak material. The access holes needed, water pressure used, and disposal of the soils should be addressed.
c) Confirmation of the deficient material removal must be made. This can be accomplished by camera inspection, CSL, or by other means acceptable to the engineer.
d) The grouting plan should include: grouting type, grout mix design including w/c ratio, complete pressure grouting timeline. The grouting timeline should include placement times, pressure, volume, refusal criteria.
3. A final confirmation of the effectiveness of the grouting should be made. This is typically accomplished by coring. The number of cores required, and depth shall be submitted to the engineer for approval prior to coring. If all the CSL tubes are still usable, a final CSL can be made for acceptance. The engineer of record for the design should be consulted for final acceptance.

Question: Per Sec 701.4.17.2.1 Installation of Pipes, “The pipes shall be filled with water and plugged or capped before shaft concrete is poured.” Why is this necessary?

The water in the tube helps to regulate the temperature of the CSL tube. Without the water, the tube will heat up from the hydrating concrete and cause de-bonding. This de-bonding from the concrete will cause erroneous CSL readings and show up as an anomaly. Typically, de-bonding is more prevalent in the upper 6 ft. of the tube. The water also serves a second purpose: it helps the energy transmission from the wall of the tube to the probes and vice versa.

Drilled shafts for non-bridge structures:

Drilled shafts for non-bridge structures are typically designed and constructed without casing. Permanent casing is not allowed except for special designs.

The shafts may be embedded into rock when soil overburden depth is inadequate for properly anchoring the foundation. If overburden soils are unstable and conduit access is not required in the perimeter of the shaft, temporary casing may be used with an oversized shaft to allow excavation into rock at the required diameter.





751.1.2.20 Substructure Type

Once the signed Bridge Memo and the Borings are received, the entire layout folder should be given to the Preliminary Detailer (requested by SPM, assigned by Structural Resource Manager). The Preliminary Detailer will copy the appropriate MicroStation drawings into their own directory. (Do not rename files) Consultants contact Structural Liaison Engineer. The Preliminary Detailer will then draw the proposed bridge on the plat and profile sheets. The bridge should also be drawn on the contracted profile for a perspective of the profile grade relative to the ground line for drainage considerations. The Preliminary Detailer will also generate a draft Design Layout Sheet and then return the layout folder to the Preliminary Designer for review.

The Preliminary Designer will then choose the substructure types for each of the bents. Pile cap bents without concrete encasement are less expensive than column bents but they should not be used at the following locations:

  • Where drift has been identified as a problem
  • Where the height of the unbraced piling is excessive and kl/r exceeds 120 (kl/r<120 is generally preferred) (take scour into account)
  • Where the bent is adjacent to traffic (grade separations)

Encased pile cap bents may be considered if economical. Embed concrete encasement 2 ft. (minimum) below the top of the lowest finished groundline elevation, unless a greater embedment is required for bridge scour. Greater embedment up to 5 or 6 ft. may be considered in situations where anticipated ground line elevation can fluctuate more severely. (Be sure to account for excavation quantities for deeper embedment.) Provision for encasing piles may be considered at the following locations:

  • Where drift is a concern and protection is required
  • Where larger radius of gyration is necessary and therefore improved buckling resistance for locations where the exposed unbraced column length is large
  • Not exclusively where the piles at the pile/wall interface may experience wet/dry cycles and/or excessive periods of ground moisture

For column bents, an economic analysis should be performed to compare drilled shafts to footings. Footings are not recommended for stream crossings where scour potential is identified. For grade separations, assume the top of drilled shaft casing is located at least one foot below the ground line. For shallow rock conditions, consideration should also be given to eliminating the cased portion of the shaft and placing the column directly over an oversized rock socket. Top of drilled shaft casing for stream crossings should consider the following criteria, and with SPM or SLE approval, select the appropriate elevation to balance risk for the anticipated conditions at time of construction:

  • 10-year flood elevation
  • 1 foot above ordinary high water elevation
  • Elevation of nearest overbank
  • 3 feet above low water elevation

End Bents are usually pile cap bents; however, if quality rock is abundant at or just below the bottom of beam elevation, a stub end bent on spread footings may be used. If you have any doubt about the suitability and uniformity of the rock, you can still use a pile cap end bent. Just include prebore to get a minimum of 10 ft. of piling. If you have concerns about temperature movements, you can require that the prebore holes be oversized to allow for this movement.

For any pile cap bents, where steel piles are to be placed near a fluctuating water line or near a ground line where aggressive soil conditions exist or anticipated to exist in the future, corrosion can result in substantial material loss in pile sections over time, either slowly or rapidly. Galvanized steel piling is required for all new pile cap bents to be used as a deterrent to both accelerated and incidental pile corrosion as commonly seen in the field. Further, conditions like known in corrosive soils, some stream crossings with known history of effects on steel piles and grounds subject to stray currents, these conditions should affect the decision of whether pile cap bents can be effectively utilized. The potential effects of corrosion and the potential deterioration from environmental conditions should always be considered in the determination and selection of the steel pile type and steel pile cross-section (size of HP pile or casing thickness), and in considering the long-term durability of the pile type in service.

Once the substructure type has been determined, re-examine your Preliminary Cost Estimate and notify the district if it needs to be adjusted.

Galvanized Steel Piles

Galvanizing shall be required for all steel piles. Utilizing galvanized steel piles and pile bracing members shall be in addition to the requirements of Standard Specifications Sec 702 except that protective coatings specified in Sec 702 will not be required for galvanized piles or galvanized bracing members.

Where galvanized steel piling is expected to be exposed to severe corrosive conditions, consideration can be given to increased steel pile thickness or consideration of a reduced loaded steel area for bearing, or conditions mitigated to prevent long term corrosivity risk . This equally applies to the potential corrosion and early deterioration of permanent steel casing used for drilled shafts though they are not required to be galvanized. For all cases, further consideration beyond normal practice should be given to investigating corrosion protection, rate of corrosion as it relates to steel thickness design and expected service life including galvanizing losses, corrosion mitigation or different substructure support in order to meet a 75 year or longer design life. For additional information refer to LRFD 10.7.5 and 10.8.1.5. Consult with the Structural Project Manager or Structural Liaison Engineer to determine options and strategy for implementation.

All Bridge and Retaining Wall Piles (For Example, abutment piles, wing wall piles, intermediate pile cap bent piles and pile cap footing piles)

All surfaces of piles shall be galvanized to a minimum galvanized penetration (elevation) or its full length based on the following guidance. The minimum galvanized penetration (elevation) shall be estimated in preliminary design and finalized in final design. The minimum galvanized penetration (elevation) or full length will be shown on the design layout.

Guidance for determining minimum galvanized penetration (elevation):

The designer shall establish the limits of galvanized structural steel pile (i.e., HP pile and CIP pile). All exposed pile plus any required length below ground shall be galvanized. Based on required galvanized pile length determine and show Minimum Galvanized Penetration (Elevation) or Full Length on the Design Layout and on the plans.

When glacial material or other hard material is identified in the geotechnical report discuss with SPM and consider galvanizing full length of pile to avoid the scenario where friction pile may potentially be cut-off once the geotechnical capacity is reached but the depth for galvanization is inadequate.

Required Pile
Galvanizing
For Nonscour		 Required Pile
Galvanizing
For Channel Scour		 Required Pile
Galvanizing
For Channel Migration
Estimated Pile Length ≤ 50 feet Full Length of Pile Full Length of Pile Full Length of Pile
Estimated Pile Length > 50 feet 20 feet (in ground)1 20 feet (in ground)1, but not less than 5 feet below max. scour depth. 20 feet (in ground)1, but not less than 5 feet below stream bed elev.
1 “In ground” is measured from finished ground line on intermediate bents, and bottom of beam cap for abutments.

For retaining walls supported on piles, the minimum galvanized penetration (elevation) for piles shall be “Full Length of Pile” for estimated pile length up to 50 feet and 15 feet below bottom of wall for estimated pile length greater than 50 feet.

For bridge end bents on piles with embankments supported by MSE walls, the minimum galvanized penetration (elevation) for piles shall be “Full Length of Pile” for estimated pile length up to 50 feet and 15 feet below top of leveling pad for estimated pile length greater than 50 feet.

Temporary Bridge Piles

Protective coatings are not required in accordance with Sec 718. Galvanized pile is not required. All HP piles driven to rock shall require pile point reinforcement.





751.1.2.24 Drilled Shafts

Drilled shafts are to be used when their cost is comparable to that of large cofferdams and footings. Other examples include when there are subsurface items to avoid (culverts, utilities, etc.) or when there are extremely high soil pressures due to slope failures.

Drilled shafts shall be constructed with a permanent casing and rock socketed.

The Final Foundation Investigation Report (or geotechnical report) for drilled shafts should supply you with the anticipated tip of casing, nominal tip resistance, nominal tip resistance factor, nominal side resistance, nominal side resistance factor as well as the recommended elevations for which the resistance values are applicable.

The Design Layout Sheet should include the following information:

  • Top of Drilled Shaft Elevation
  • Anticipated Tip of Casing Elevation
  • Anticipated Top of Sound Rock Elevation
Bent Elevation Nominal Axial Compressive Resistance
(Side Resistance) (ksf)		 Side Resistance Factor for
Strength Limit State		 Nominal Axial Compressive Resistance
(Tip Resistance) (ksf)		 Tip Resistance Factors for
Strength Limit States
 





751.4.1 Reinforced Concrete

Classes of Reinforced Concrete

Below are classes of concrete for each type or portion of structure:

Box Culverts B-1
Retaining Walls B or B-1
Superstructure (General) B-2
Curbs and Parapets B-1
Type A, B, C, D, G and H Barriers B-1
Sidewalks B-2
Raised Median B-2
Slabs B-2
Box Girders B-2
Deck Girders B-2
Prestressed Precast Panels A-1
Prestressed I - Girders A-1
Prestressed Double -Tee Girders A-1
Integral End Bents (Above lower construction joint) B-2
Semi-Deep Abutments (Above construction joint under slab) B-2
Substructure (General) B
Integral End Bents (Below lower construction joint) B
Non-Integral End Bents B
Semi-Deep Abutments (Below construction joint under slab) B
Intermediate Bents B (*)
Intermediate Bent Columns, End Bents (Below construction
joint at bottom of slab in Cont. Conc. Slab Bridges)		 B-1
Footings B
Drilled Shafts (except per Standard Plans 903.15) B-2
Drilled Shafts (per Standard Plans 903.15) B
Cast-In-Place Pile B-1
(*) In special cases when a stronger concrete is necessary for design, Class B-1 may be considered for intermediate bents (caps, columns, tie beams, web beams, collision walls and/or footings).
Unit Stresses of Reinforced Concrete
Class of Concrete Aggregate Maximumsize (Inches) Cement Factor (barrels percubic yard) f′c (psi) fc (psi) n (*) Ec (ksi)
A-1 3/4 1.6 (Min.) 5,000 2,000 6 4074
B 1 1.4 (Min.) 3,000 1,200 10 3156
B-1 1 1.6 (Min.) 4,000 1,600 8 3644
B-2 1 1.875 (Min.) 4,000 1,600 8 3644
(*) Values of n for computations of strength only.
Reinforcing Steel
Reinforcing Steel (Grade 60) Fy = 60 ksi






751.37.1.2 Materials

Commentary for EPG 751.37.1.2 Materials

Concrete used for drilled shaft for traffic structures in accordance with standard plan 903.15 shall be Class B concrete with minimum compressive strength, f’c = 3 ksi. For all other drilled shaft construction concrete shall be Class B-2 with minimum compressive strength, f’c = 4 ksi.





751.37.1.3 Casing

Commentary for EPG 751.37.1.3 Casing

Drilled shafts for bridge structures:

All drilled shafts shall have permanent casing installed through overburden soils to prevent caving of these soils during construction. Drilled shafts shall be socketed into bedrock. Welded or seamless steel permanent casing shall be in accordance with Sec 701.

Rock sockets shall be uncased.

Permanent Casing Thickness Design and Plan Reporting:

Any drilled shaft for a major bridge over a river or lake or any drilled shaft longer than 80 feet or any drilled shaft greater than 6 feet in diameter shall have a minimum casing thickness of 1/2 inch specified unless a greater thickness is required by design for strength. The thickness of casing in either case shall be shown on the bridge plans and noted as a minimum.
All other drilled shafts shall not have a minimum casing thickness specified unless a specific thickness is required by design for strength. The minimum thickness in the latter case shall be shown on the bridge plans and noted as a minimum.
For drilled shaft stiffness computations and load distribution analysis, use the minimum casing thickness required. When a minimum casing thickness is not required, assume a casing thickness of 3/8” for the analysis.






751.37.1.5 Related Provisions

Commentary for EPG 751.37.1.5 Related Provisions

The provisions of these guidelines were developed presuming that design parameters required to apply the provisions are established following current MoDOT site characterization protocols as described in EPG 321. Specific attention is drawn to EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation. The provisions provided in these guidelines presume that parameter variability, as generally represented by the coefficient of variation (COV), is established following procedures in EPG 321.3.

Sign structure drilled shaft supports are the exception. Sign structure standard drilled shafts are developed using assumed soil properties and following AASHTO LRFD Bridge Design Specifications 9th Edition for design. Site specific designs for drilled shafts for sign structure support may also follow AASHTO LRFD Bridge Design Specifications 9th Edition if there is not enough geotechnical information available to establish the COV.





751.37.1.6 Drilled Shaft General Detail Considerations

For Seismic detail requirements for seismic design category, SDC B, C and D, See EPG 751.9.1.2 LRFD Seismic Details.

Pay items shown in above table are for example only, show actual pay items and quantities in plan details for specific project.

Notes:

(1) Number of pipes (equally spaced) for Sonic Logging Testing (for bridge structures only):
Diameter ≤ 2.5 ft: 2 pipes
Diameter >2.5 ft but ≤ 3.5 ft: 3 pipes
Diameter >3.5 ft but ≤ 5.0 ft: 4 pipes
Diameter >5.0 ft but ≤ 8.0 ft: 5 pipes
Diameter >8.0 ft: 6 pipes
Single diameter reinforcing cage is typically used. Modify details based on design for single or multiple-diameter cages and splice location(s).
See EPG 751.37.1.3 for casing requirements for bridge structures and non-bridge structures.
When determining P bar diameter for barbill, assume 3/8” casing unless otherwise specified.
See EPG 751.50, G8, for notes to include for drilled shafts and rock sockets (starting at G8.1).
(2) See EPG 751.37.1.1 Dimensions and Nomenclature for Design Aid: Minimum Rock Socket Length.
(3) When difference between drilled shaft and column diameter is 6" a single reinforcement cage is typically used for the socket and shaft and the vertical reinforcement extends into the column. A separate column steel cage is then placed around the protruding shaft reinforcement without requiring an adjustment to minimum cover for rock socket or column reinforcement. When difference between drilled shaft and column diameter is 12” either the vertical column steel or dowels will need to be extended into the shaft or the cover in the socket and shaft will need to be increased to allow the shaft reinforcement to extend into the column. In the former scenario an optional construction joint is recommended as discussed in note 4 for oversized shafts. In the latter scenario the same number of vertical bars should be used in the shaft and column to allow the shaft bars to be tied to the column cage. Any reduction in cage diameter required for fit-up shall be considered in design.
(4) When difference between drilled shaft and column diameter is greater than 12" (oversized shaft generally 18" to 24" larger than column), show "Optional construction joint" at bottom of column/dowel reinforcement in the drilled shaft and use EPG 751.50 Standard Detailing Notes G8.8 and G8.9 in plan details.
Bridge Standard Drawings
(Drilled Shafts - DSS → As Built Drilled Shaft Data [DSS_01])
As Built Drilled Shaft Data (PDF)





751.37.2 General Design Procedure and Limit States

Commentary for EPG 751.37.2 General Design Procedure and Limit States

Drilled shafts should be sized (diameter and length) to support the required factored loads in the most cost effective manner possible without excessive deflections. The initial diameter and length of drilled shafts are generally established considering vertical loading at the strength limit state(s) according to EPG 751.37.3. The resulting shaft should then be evaluated at the axial and lateral serviceability limit states (settlement and lateral deflection) according to EPG 751.37.4 and EPG 751.37.5, where the shaft dimensions shall be adjusted if serviceability requirements are not satisfied.

The Strength Limit State and applicable Extreme Event Limit States shall be investigated when calculating the soil and structural resistance of the drilled shaft. The Service I Limit State shall be used when evaluating lateral deflection and settlement.

Guidance

There is one type of drilled shaft construction for bridge structures. There are three types of drilled shaft construction for non-bridge structures, but only two types need be considered for design. See EPG 751.37.1.3 Casing.

Drilled shafts for bridge structures:
Permanently cased shaft through soil and socketed into rock. A reduced shaft diameter for rock socket is required. This case shall be used for all MoDOT bridge structures. For axial loading and settlement computations substitute D with Ds and L with Ls which are equal to the diameter and length of the rock socket since the required resistance to loading and settlement are computed for segment of the shaft in rock only (Rock sockets to be installed through casing shall have diameters 6” less than the inside diameter of the casing to allow for clearance and insertion of rock excavation re-tooling equipment).
Drilled shafts for non-bridge structures:
1. Uncased shaft through soil and not socketed into rock. For axial loading and settlement computations use D = diameter of shaft.
2. Uncased shaft through soil and rock. Similar to (1) because the shaft diameter is assumed to be constant between soil and rock.
3. Temporarily cased shaft through soil with an uncased and reduced or same shaft diameter in rock. This method is optional for the contractor in limited scenarios and requires the shaft in soil to be oversized by six inches with respect to the shaft diameter shown on the plans.

Permanently cased shafts shall not be allowed to use frictional resistance of the soil for either a drilled shaft with or without a rock socket.

Temporarily cased shafts may use the frictional resistance of the soil only for the case where a rock socket is not used (see the Geotechnical Section).

Note on Definitions:

1. Where L,i is defined, Li shall mean the length of the shaft segment through soil or through rock.
2. Where L is defined, L shall mean overall shaft length including the length of the rock socket.





751.37.3 Design for Axial Loading at Strength Limit State

Commentary for EPG 751.37.3 Design for Axial Loading at Strength Limit State

Geotechnical resistance to axial loading at the relevant strength limit state shall be computed as the sum of tip resistance and side resistance unless conditions are present that may prevent reliable mobilization of tip resistance (e.g. karst conditions with known or likely voids that cannot be specifically identified or characterized). Shafts should be sized such that the factored geotechnical resistance to axial loads exceeds the factored axial loads:

RR=RsR+RpR≥γQ (consistent units of force) Equation 751.37.3.1

where:

RR = factored axial shaft resistance (consistent units of force),
RsR = factored side resistance (consistent units of force),
RpR = factored tip resistance (consistent units of force) and
γQ = factored load for the appropriate strength limit state (consistent units of force).

Tip resistance and side resistance shall be computed according to the provisions of EPG 751.37.3 for the material type(s) encountered. The Structural Project Manager or Structural Liaison Engineer shall be consulted before utilizing design methods other than those provided in EPG 751.37.3 for calculating the geotechnical resistance of drilled shafts.

The factored side resistance for drilled shafts shall be established from factored unit side resistance values for the relevant soil/rock conditions as provided in this article. For stratified ground conditions or where the shaft dimensions change (e.g. at tip of temporary casing for non-bridge structure, or at top of rock socket for bridge structure), the shaft shall be divided into segments with practically uniform shaft geometry and soil/rock properties and unit side resistance values determined for each shaft segment. The total factored side resistance shall then be computed as the sum of the factored resistance values for each shaft segment:

RsR=∑i=1n(qsR−i⋅As−i)=∑i=1n(ϕqs−i⋅qs−i⋅π⋅Di⋅Li) (consistent units of force) Equation 751.37.3.2

where:

n = number of shaft segments,
qsR−i=ϕqs−i⋅qs−i = factored unit side resistance for shaft segment i (consistent units of stress),
As−i=π⋅Di⋅Li = perimeter interface area for shaft segment i (consistent units of area),
ϕqs−i = resistance factor for unit side resistance along shaft segment i (dimensionless),
qs−i = nominal unit side resistance along shaft segment i (consistent units of stress),
Di = shaft diameter for shaft segment i (consistent units of length), and
Li = length of shaft segment i (consistent units of length).

ϕqs−i and qs−i shall be determined in accordance with the provisions of this article, based on the material type present along the respective shaft segment.

Side resistance shall generally be neglected or reduced, as recommended by the Geotechnical Section, over shaft segments with permanent casing and over any length of rock socket that is deemed unusable.

The factored tip resistance for drilled shafts shall be established from factored unit tip resistance values for the relevant soil/rock conditions as provided in this article. The appropriate tip resistance shall be established for the soil/rock located between the tip of the shaft and two diameters below the tip of the shaft. The factored tip resistance shall be computed as

RpR=qpR⋅Ap=ϕqp⋅qp⋅π⋅D24 (consistent units of force) Equation 751.37.3.3

where:

qpR=ϕqp⋅qp = factored unit tip resistance (consistent units of stress),
Ap=π⋅D24 = cross-sectional area of the shaft at the tip (consistent units of area),
ϕqp = resistance factor for unit tip resistance (dimensionless),
qp= nominal unit tip resistance (consistent units of stress), and
D = shaft diameter at the tip of the shaft (consistent units of length).

ϕqp and qp shall be determined in accordance with the provisions of this article, based on the material type present within a depth of 2D below the tip of the shaft.

Tip resistance shall be neglected, as recommended by the Geotechnical Section, when the shaft tip is located within karstic rock or other conditions where tip resistance cannot be reliably determined.

The specific methods and resistance factors for determining nominal and factored side and tip resistance shall be selected based on the material type(s) present along the sides and beneath the tip of the shaft:

  • EPG 751.37.3.1 shall generally be followed to estimate resistance for shafts in rock from results of uniaxial compression tests on intact rock core with uniaxial compressive strengths (qu ) greater than 100 ksf;
  • EPG 751.37.3.2 shall generally be followed to estimate resistance for shafts in weak rock from results of uniaxial compression tests on rock core with uniaxial compressive strengths (qu ) greater than 5 ksf but less than 100 ksf;
  • EPG 751.37.3.3 shall generally be followed to estimate resistance for shafts in weak rock from results of Standard Penetration Tests with equivalent N-values (Neq ) less than 400 blows/foot;
  • EPG 751.37.3.4 shall generally be followed to estimate resistance for shafts in weak rock from results of Texas Cone Penetration Tests with measured penetrations (TCP) greater than 1 inch/100 blows but less than 10 inches/100 blows;
  • EPG 751.37.3.5 shall generally be followed to estimate resistance for shafts in weak rock from results of Point Load Index Tests with Point Load Indices (Is(50) ) less than 40 ksf;
  • EPG 751.37.3.6 shall generally be followed to estimate resistance for shafts in cohesive soils with undrained shear strengths (su ) less than 5 ksf; and
  • EPG 751.37.3.7 shall generally be followed to estimate resistance for shafts in cohesionless soils.

Additional guidance on selection of specific methods and resistance factors based on the material types encountered is provided in the commentary to these guidelines.







751.37.3.7 Axial Resistance for Individual Drilled Shafts in Cohesionless Soils

Commentary for EPG 751.37.3.7 Axial Resistance for Individual Drilled Shafts in Cohesionless Soils

Side Resistance for Drilled Shafts in Cohesionless Soils

The nominal unit side resistance for shaft segments located in cohesionless soils shall be computed using the “β-method” as

qs=β⋅σv' (consistent units of stress) Equation 751.37.3.21

where:

qs = nominal unit side resistance for the shaft segment (consistent units of stress),
β = an empirical correlation factor (dimensionless) and
σ'v = average vertical effective stress for the soil along the shaft segment (consistent units of stress).

The value for β shall be taken as (O’Neill and Reese, 1999)

β=1.5−0.135z (for N60 ≥ 15) Equation 751.37.3.22a
β=N6015⋅(1.5−0.135z) (for N60 < 15) Equation 751.37.3.22b

where 0.25 ≤ β ≤ 1.2 and

z = depth below ground surface to center of shaft segment (ft.) and
N60 = average SPT N-value corrected for hammer efficiency (blows/ft).

If permanent casing is used, the side resistance shall be ignored for the cased portion.

The resistance factor ϕqs to be applied to the nominal unit side resistance shall be taken as 0.55 (LRFD Table 10.5.5.2.4-1).

Tip Resistance for Drilled Shafts in Cohesionless Soils

The nominal unit tip resistance for shafts founded on cohesionless soils shall be computed from corrected SPT N-values, N60 (O’Neill and Reese, 1999).

For N_60≤50:

qp=1.2⋅N60≤60ksf (ksf) Equation 751.37.3.23

where:

qp = nominal unit tip resistance for the shaft (ksf) and
N60 = average SPT N-value corrected for hammer efficiency (blows/ft).

For N60 ≥ 50:

qp=0.59⋅σv'⋅(N60(paσv'))0.8 (ksf) Equation 751.37.3.24

where:

qp = nominal unit tip resistance for the shaft (ksf),
N60 = average SPT N-value corrected for hammer efficiency (blows/foot),
pa = 2.12 ksf = atmospheric pressure (ksf).
σv' = vertical effective stress for the soil at the tip of the shaft (ksf).

Note that these expressions are dimensional so values must be entered in the units specified.

The resistance factor ϕqp shall be taken as 0.50 for Equation 751.37.3.23 and as 0.55 for Equation 751.37.3.24.







751.37.4.1 Settlement of Individual Drilled Shafts using Approximate Method

Commentary on EPG 751.37.4.1 Settlement of Individual Drilled Shafts using Approximate Method

Prediction of factored settlement due to factored service loads shall be determined as follows depending on the magnitude of factored loads relative to the magnitude of factored side and tip resistance:

If γQ≤RsR+0.1RpR:

δR=0.005⋅D⋅γQRsR+0.1RpR+δeR (consistent units of lengths) Equation 751.37.4.3

where:

γQ = factored load for the appropriate serviceability limit state (consistent units of force),
RsR = total factored side resistance determined according to the provisions of this article (consistent units of force),
RpR = factored tip resistance determined according to the provisions of this article (consistent units of force),
δR = factored total settlement of shaft due to factored service loads (consistent units of length),
D = shaft diameter (consistent units of length) and
δeR = factored elastic compression of the unsupported length of the shaft (consistent units of length).

If RsR+0.1RpR≤γQ≤RsR+RpR :

δR=0.005⋅D+0.045⋅D⋅(γQ−RsR−0.1RpR0.9⋅RpR)+δeR (consistent units of lengths) Equation 751.37.4.4

where:

γQ = factored load for the appropriate serviceability limit state (consistent units of force),
RsR = total factored side resistance determined according to the provisions of this article (consistent units of force),
RpR = factored tip resistance determined according to the provisions of this article (consistent units of force),
δR = factored total settlement of shaft due to factored service load (consistent units of length),
D = shaft diameter (consistent units of length) and
δeR = factored elastic compression of the unsupported length of the shaft (consistent units of length).

Note that if γQ≥RsR+RpR, the factored service load exceeds the maximum factored resistance of the shaft and the limit state cannot be satisfied without increasing the dimensions of the shaft.

The factored side resistance in Equations 751.37.4.3 and 751.37.4.4 shall be established from factored unit side resistance values for the relevant soil/rock conditions as provided in this article. For stratified ground conditions or where the shaft dimensions change, the shaft shall be divided into segments with practically uniform shaft geometry and soil/rock properties and unit side resistance values determined for each shaft segment. The total factored side resistance shall then be computed as the sum of the factored resistance values for each shaft segment:

RsR=∑i=1n(qsR−1⋅As−i)=∑i−1n(ϕδs−i⋅qs−i⋅π⋅Di⋅Li) (consistent units of force) Equation 751.37.4.5

where:

n = number of shaft segments,
qsR−i=ϕδs−i⋅qs−i = factored unit side resistance for shaft segment i (consistent units of stress),
As−i=π⋅Di⋅Li = perimeter interface area for shaft segment i (consistent units of area),
ϕδs−i = settlement resistance factor for side resistance along shaft segment i (dimensionless),
qs-i = nominal unit side resistance along shaft segment i (consistent units of stress),
Di = shaft diameter for shaft segment i (consistent units of length) and
Li = length of shaft segment i (consistent units of length).

Values for qs-i shall be determined in accordance with the provisions of EPG 751.37.3, based on the material type present along the respective shaft segments. Values for ϕδs−i shall be established as provided subsequently in this article. Side resistance shall generally be neglected or reduced, as recommended by the Geotechnical Section, over shaft segments with permanent casing and over any length of rock socket that is deemed unusable for consistency with evaluations performed for strength limit states.

The factored tip resistance in Equations 751.37.4.3 and 751.37.4.4 shall be established from factored unit tip resistance values for the relevant soil/rock conditions as provided in this article. The appropriate tip resistance shall be established for the soil/rock located between the tip of the shaft and a distance of 2D below the tip of the shaft. The factored tip resistance shall be computed as

RpR=qpR⋅Ap=ϕδp⋅qp⋅π⋅D24 (consistent units of force) Equation 751.37.4.6

where:

qpR=ϕδp⋅qp = factored unit tip resistance (consistent units of stress),
Ap=π⋅D24 = cross-sectional area of the shaft at the tip (consistent units of area),
ϕδp = settlement resistance factor for tip resistance (dimensionless),
qp = nominal unit tip resistance (consistent units of stress) and
D = shaft diameter at the tip of the shaft (consistent units of length).

The value for qp shall be determined in accordance with the provisions of EPG 751.37.3, based on the material type present within a depth of 2D below the tip of the shaft. The value for ϕδp shall be established as provided subsequently in this article. For consistency with evaluations for strength limit states, tip resistance shall be neglected, as recommended by the Geotechnical Section, when the shaft tip is located within karstic rock or other conditions where tip resistance cannot be reliably determined.

The factored elastic compression of the unsupported length of the shaft shall be determined as

δeR=γQ(L−Ls)ϕδe⋅EpAp (consistent units of length) Equation 751.37.4.7

where:

δeR = factored elastic compression of the unsupported length of the shaft (consistent units of length),
γQ = factored load for the appropriate serviceability limit state (consistent units of force),
L = overall shaft length (consistent units of length),
Ls = length of the rock socket (consistent units of length),
Ep = nominal modulus of elasticity for the shaft (consistent units of stress),
Ap = nominal shaft area (consistent units of area) and
ϕδe = settlement resistance factor for elastic compression of the shaft.

Values for the settlement resistance factor for elastic compression of the shaft shall be taken from Table 751.37.4.1 according to the operational importance of the structure.

Table 751.37.4.1 Settlement resistance factors for elastic compression of drilled shafts

Operational Importance Settlement Resistance Factor, Φδe
Minor or Low Volume Route 0.68
Major Route 0.64
Major Bridge <$100 million 0.61
Major Bridge >$100 million 0.60


Settlement Resistance Factors for Approximate Method for Drilled Shafts in Rock

Settlement resistance factors to be applied to side resistance for shaft segments through rock shall be determined from Figure 751.37.4.1.1 based on the coefficient of variation of the mean uniaxial compressive strength, COVqu‾. Values for COVqu‾ shall be determined in accordance with EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation to reflect the variability of the mean uniaxial compressive strength for the rock over the shaft segment. Settlement resistance factors to be applied to tip resistance for shafts founded on rock shall similarly be determined from Figure 751.37.4.1.2 based on values for COVqu‾ that reflect the variability of the mean uniaxial compressive strength for the rock over the distance 2Ds below the tip of the shaft.

Fig. 751.37.4.1.1 Settlement resistance factors for side resistance of drilled shafts in rock from uniaxial compression test measurements using approximate method.
Fig. 751.37.4.1.2 Settlement resistance factors for tip resistance of drilled shafts in rock from uniaxial compression test measurements using approximate method.

Settlement Resistance Factors for Approximate Method for Drilled Shafts in Weak Rock from Uniaxial Compression Tests on Rock Core

Settlement resistance factors to be applied to side resistance for shaft segments through weak rock shall be determined from Figure 751.37.4.1.3 based on the coefficient of variation of the mean uniaxial compressive strength, COVqu‾. Values for COVqu‾ shall be determined in accordance with EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation to reflect the variability of the mean uniaxial compressive strength for the rock over the shaft segment. Settlement resistance factors to be applied to tip resistance for shafts founded on weak rock shall similarly be determined from Figure 751.37.4.1.4 based on values for COVqu‾ that reflect the variability of the mean uniaxial compressive strength for the rock over the distance 2Ds below the tip of the shaft.


Fig. 751.37.4.1.3 Settlement resistance factors for side resistance of drilled shafts in weak rock from uniaxial compression test measurements using approximate method.
Fig. 751.37.4.1.4 Settlement resistance factors for tip resistance of drilled shafts in weak rock from uniaxial compression test measurements using approximate method.

Settlement Resistance Factors for Approximate Method for Drilled Shafts in Weak Rock from Standard Penetration Test Measurements

Settlement resistance factors to be applied to side resistance for shaft segments through weak rock shall be determined from Figure 751.37.4.1.5 based on the coefficient of variation of the mean equivalent SPT N-value, COVNeq‾. Values for COVNeq‾ shall be determined in accordance with EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation to reflect the variability of the mean equivalent N-value over the shaft segment. Settlement resistance factors to be applied to tip resistance for shafts founded on weak rock shall similarly be determined from Figure 751.37.4.1.6 based on values for COVNeq‾ that reflect the variability of the mean equivalent N-value over the distance 2Ds below the tip of the shaft.


Fig. 751.37.4.1.5 Settlement resistance factors for side resistance of drilled shafts in weak rock from Standard Penetration Test measurements using approximate method.
Fig. 751.37.4.1.6 Settlement resistance factors for tip resistance of drilled shafts in weak rock from Standard Penetration Test measurements using approximate method.

Settlement Resistance Factors for Approximate Method for Drilled Shafts in Weak Rock from Texas Cone Penetration Test Measurements

Settlement resistance factors to be applied to side resistance for shaft segments through weak rock shall be determined from Figure 751.37.4.1.7 based on the coefficient of variation of the mean TCP-value, COVTCP‾. Values for COVTCP‾ shall be determined in accordance with EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation to reflect the variability of the mean TCP-value over the shaft segment. Settlement resistance factors to be applied to tip resistance for shafts founded on weak rock shall similarly be determined from Figure 751.37.4.1.8 based on values for COVTCP‾ that reflect the variability of the mean TCP-value over the distance 2Ds below the tip of the shaft.


Fig. 751.37.4.1.7 Settlement resistance factors for side resistance of drilled shafts in weak rock from Texas Cone Penetration Test measurements using approximate method.
Fig. 751.37.4.1.8 Settlement resistance factors for tip resistance of drilled shafts in weak rock from Texas Cone Penetration Test measurements using approximate method.

Settlement Resistance Factors for Approximate Method for Drilled Shafts in Weak Rock from Point Load Index Test Measurements

Settlement resistance factors to be applied to side resistance for shaft segments through weak rock shall be determined from Figure 751.37.4.1.9 based on the coefficient of variation of the mean Is(50)-value, COVIs(50)‾. Values for COVIs(50)‾ shall be determined in accordance with EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation to reflect the variability of the mean Is(50)-value for the rock over the shaft segment. Settlement resistance factors to be applied to tip resistance for shafts founded on weak rock shall similarly be determined from Figure 751.37.4.1.10 based on values for COVIs(50)‾ that reflect the variability of the mean Is(50)-value for the rock over the distance 2Ds below the tip of the shaft.


Fig. 751.37.4.1.9 Settlement resistance factors for side resistance of drilled shafts in weak rock from Point Load Index Test measurements using approximate method.
Fig. 751.37.4.1.10 Settlement resistance factors for tip resistance of drilled shafts in weak rock from Point Load Index Test measurements using approximate method.


Settlement Resistance Factors for Approximate Method for Drilled Shafts in Cohesive Soils

Settlement resistance factors to be applied to side resistance for shaft segments through cohesive soil shall be determined from Figure 751.37.4.1.11 based on the coefficient of variation of the mean undrained shear strength, COVsu‾. Values for COVsu‾ shall be determined in accordance with EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation to reflect the variability of the mean undrained shear strength for the soil over the shaft segment. Settlement resistance factors to be applied to tip resistance for shafts founded on cohesive soil shall similarly be determined from Figure 751.37.4.1.12 based on values for COVsu‾ that reflect the variability of the mean undrained shear strength for the soil over the distance 2D below the tip of the shaft.


Fig. 751.37.4.1.11 Settlement resistance factors for side resistance of drilled shafts in cohesive soil from undrained shear strength measurements using approximate method.
Fig. 751.37.4.1.12 Settlement resistance factors for tip resistance of drilled shafts in cohesive soil from undrained shear strength measurements using approximate method.

For shafts founded in soft cohesive soils, consideration shall also be given to including additional settlement induced from time dependent consolidation of the soil.

Settlement Resistance Factors for Approximate Method for Drilled Shafts in Cohesionless Soils

Settlement evaluations for individual drilled shafts in cohesionless soils shall be designed according to applicable sections of the current AASHTO LRFD Bridge Design Specifications.







751.37.6.1 Reinforcement Design

Drilled shaft structural resistance shall be designed similarly to reinforced concrete columns. The Strength Limit State and applicable Extreme Event Limit State load combinations shall be used in the reinforcement design.

Longitudinal reinforcing steel shall extend below the point of fixity of the drilled shaft at least 10 ft. in accordance with LRFD 10.8.3.9.3 or the required bar development length whichever is larger.

If permanent casing is used, and the shell consists of a smooth pipe greater than 0.12 in. thick, it may be considered load carrying. An 1/8" shall be subtracted off of the shell thickness to account for corrosion. Casing could also be corrugated metal pipe. If casing is assumed to contribute to the structural resistance, the plans should indicate the minimum thickness of casing required.

Minimum clear spacing between longitudinal bars as well as between transverse bars shall not be less than five times the maximum aggregate size or 5 in. (LRFD 10.8.3.9.3).

For rock sockets use 3” min. clear cover. For drilled shafts for sign structure support, use 3” min. clear cover for all shaft diameters.

For longitudinal reinforcement, splicing shall be in accordance with LRFD 5.10.8.4.

For transverse reinforcement, lap splices for closed circular stirrups/ties shall be provided and staggered in accordance with LRFD 5.10.4.3. Lap length of 1.3 ld (Class B) for closed stirrups/ties shall be provided in accordance with LRFD 5.10.8.2.6d.

For lap length, see EPG 751.5.9.2.8.1 Development and Lap Splice General.







Commentary on EPG 751.37.1.3 Casing

Temporary or permanent casing is commonly required to support the shaft excavation during construction to prevent caving of overburden soils. Use of permanent casing generally simplifies construction by avoiding the need for multiple cranes to simultaneously place concrete and extract the casing and reduces the risk of problems during concrete placement. However, use of either temporary or permanent casing will generally reduce the side resistance of the constructed shaft over the cased length. Alternatives to use of casing for non-bridge structures include use of mineral or polymer slurry to maintain the stability of the excavation during construction, or use of no casing and no slurry when soil/rock conditions will permit the shafts to be constructed without caving of the excavation walls.

Permanent casing may also be required to provide structural resistance, especially when lateral loads are substantial (see EPG 751.37.6). For example, permanent casing may be required to:

  • Achieve the required flexural resistance of the drilled shaft
  • Resist large lateral loads for bridges located in seismic areas
  • Facilitate shaft construction through water
  • Support the shaft excavation when there is insufficient head room available for casing recovery






751.38.1.1 Dimensions and Nomenclature

Dimensions to be established in design include the bearing depth (depth to footing base) and the footing dimensions shown in Figure 751.38.1.1. Table 751.38.1.1 defines each dimension and provides relevant minimum and/or maximum values for the respective dimension.

Fig. 751.38.1.1 Nomenclature used for spread footings.

Table 751.38.1.1 Summary of footing dimensions with minimum and maximum values

Dimension Description Minimum Value Maximum Value Comment
D Column diameter 12” -- --
B Footing width D+24” -- Min. 3” increments
L Footing length D+24”1 -- Min. 3” increments
A Edge distance in width direction 12” -- --
A’ Edge distance in length direction 12” -- --
t Footing thickness 30” or D2 72” Min. 3” increments
1 Minimum of 1/6 x distance from top of beam to bottom of footing
2 For column diameters ≥ 48”, use minimum value of 48”. Sign support structures may utilize a minimum thickness of 24”.

The nomenclature used in these guidelines has intentionally been selected to be consistent with that used in the AASHTO LRFD Bridge Design Specifications (AASHTO, 2009) to the extent possible to avoid potential confusion with methods provided in those specifications. By convention, references to other provisions of the MoDOT Engineering Policy Guide are indicated as “EPG XXX.XX” throughout these guidelines where the Xs are replaced with the appropriate article numbers. Similarly, references to provisions within the AASHTO LRFD Bridge Design Specifications are indicated as “LRFD XXX.XX”.





751.38.1.2 General Design Considerations

Commentary for EPG 751.38.1.2 General Design Considerations

Footings shall be founded to bear a minimum of 36 in. below the finished elevation of the ground surface. In cases where scour, erosion, or undermining can be reasonably anticipated, footings shall bear a minimum of 36 in. below the maximum anticipated depth of scour, erosion, or undermining.

Footing size shall be proportioned so that stresses under the footing are as uniform as practical at the service limit state.

Long, narrow footings supporting individual columns should be avoided unless space constraints or eccentric loading dictate otherwise, especially on foundation material of low capacity. In general, spread footings should be made as close to square as possible. The length to width ratio of footings supporting individual columns should not exceed 2.0, except on structures where the ratio of longitudinal to transverse loads or site constraints makes use of such a limit impractical. For spread footings supporting overhead sign structures the length to width ratio of footings supporting individual columns may be as high as 4.0.

Footings located near to rock slopes (e.g. rock cuts, river bluffs, etc.) shall be located so that the footing is founded beyond a prohibited region established by a line inclined from the horizontal passing through the toe of the slope as shown in Figure 751.38.1.2. The boundary of the prohibited region shall be established by the Geotechnical Section. For the purposes of this provision, the toe of the slope shall be the point on the slope that produces the most severe location for the active zone. Exceptions to this provision shall only be made with specific approval of the Geotechnical Section and shall only be granted if overall stability can be demonstrated as provided in EPG 751.38.7.

Fig. 751.38.1.2 Prohibited region for spread footings placed near rock slopes unless exception is specifically approved by MoDOT Geotechnical Section.

Footings located near to soil slopes shall be evaluated for overall stability as provided in EPG 751.38.7 unless they are located a minimum distance of 2B beyond the crest of the slope.







751.38.1.3 Related Provisions

The provisions in these guidelines were developed presuming that design parameters required to apply the provisions are established following current MoDOT site characterization protocols as described in EPG 321. Specific attention is drawn to EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation. The provisions provided in this subarticle presume that parameter variability, as generally represented by the coefficient of variation (COV), is established following procedures in EPG 321.3.

Sign structure spread footing supports are the exception. Sign structure standard spread footings are developed using assumed soil properties and following AASHTO LRFD Bridge Design Specifications 9th Edition for design. Site specific designs for spread footings for sign structure support may also follow AASHTO LRFD Bridge Design Specifications 9th Edition if there is not enough geotechnical information available to establish the COV.






751.38.8.3 Details

Hooks at the end of reinforcement are not required for spread footings supporting sign structures. Include reinforcement near the top of spread footings supporting sign structures as required for uplift and in accordance with design requirements.





G8. Drilled Shaft

(G8.1) Include underlined portion when a minimum thickness is required and shown on the plans as minimum.

Thickness of permanent steel casing shall be as shown on the plans and in accordance with Sec 701.

(G8.2) Note may not be required with drilled shafts for high mast tower lighting.

An additional 4 feet has been added to V-bar lengths and additional __-#_-P___ bars have been added in the quantities, if required, for possible change in drilled shaft or rock socket length. The additional V-bar length shall be cut off or included in the reinforcement lap if not required. The additional P bars shall be spaced similarly to that shown in elevation, if required, or to a lesser spacing if not required, but not less than 6-inch centers.

(G8.3) Note not required with drilled shafts for high mast tower lighting.

Sonic logging testing shall be performed on all drilled shafts and rock sockets.

(G8.4) Note to be used only with Drilled Shafts for High Mast Tower Lighting.

Drilling slurry, if used, shall require desanding.

(G8.5) Note to be used only with Drilled Shafts for High Mast Tower Lighting. Drilled shaft diameter is required to be at least 21 in. greater than the largest anticipated anchor bolt circle diameter per the DSP - High Mast Tower Lighting.

The following non-factored base reactions were used to design the drilled shafts for the       ft. high mast lighting towers: overturning moment = * kip-foot, base shear = * kip and axial force = * kip.
 *Values used in the design of the drilled shaft.

(G8.6) Use the following note only when the tops of drilled shafts are ≤ 3'-0" below the ground surface at centerline column / drilled shaft. Otherwise excavation quantity to the top of drilled shafts needs to be figured. Excavation diameter limit will be the 3'-0" larger than the column diameter above the drilled shaft.

The cost of any required excavation to the top of the drilled shafts will be considered completely covered by the contract unit price for other items.

(G8.7)

The tip of casing shall not extend into the rock socket elevation range reported in the Foundation Data table without approval by the engineer.

(G8.8) Use the following note when non-contact or contact lap is required at the top of drilled shaft between column/dowel reinforcement and drilled shaft reinforcement.

Column or dowel reinforcement shall be placed prior to pouring drilled shaft concrete in the area of the lap. Dowel bar or column reinforcement shall not be inserted after drilled shaft pour is complete.

(G8.9) For oversized shafts, use the following note in conjunction with callout for optional construction joint near top of drilled shaft.

Remove sediment laitance and weak concrete to sound concrete prior to setting column/dowel reinforcement if optional construction joint is used.






Category:901 Lighting

Nonstandard Lighting Structures

If any lighting installation being considered will use a special or nonstandard structure or with dimensions exceeding those shown in the Standard Plans, Traffic should be consulted early in the project planning regarding the installation’s feasibility and necessary contract provisions. Examples of this situation are high mast lighting and exceeding lengths on the Standard Plans.

Since designing details for nonstandard installations is typically performed by an outside engineer employed by the contractor or producer and is certified to MoDOT, the project contract documents must include appropriate requirements about the design standards used. Since structures beyond MoDOT's standard designs are involved, a performance-based specification of the design signed and sealed by a Missouri Registered Professional Engineer is needed from the contractor. Certification to the current AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals including the latest fatigue provisions is required. For standard detailing notes regarding drilled shafts for High Mast Tower Lighting, see [[751.50_Standard_Detailing_Notes#G8._Drilled_Shaft|EPG 751.50 Standard Detailing Notes G8.4 and G8.5].







901.7.6 High Mast Lighting

High mast lighting is principally used at complex interchanges and lights a large area by a group of luminaires mounted in a fixed orientation at the top of a tall mast, generally 80 ft. or taller. The district must authorize high mast lighting. The request for high mast lighting conceptual approval is to be included with the lighting warrants. Data supporting the selection of pole height, pole location and type of luminaires is to be included with the preliminary lighting plan. Where high mast lighting is used at complex interchanges, adaptation lighting is recommended for each section where vehicles enter and leave the interchange.

The district is responsible for all bid items associated with high mast lighting and to design the foundation and the structure above the foundation for inclusion in the project plans.

For standard detailing notes regarding drilled shafts for High Mast Tower Lighting, see [[751.50_Standard_Detailing_Notes#G8._Drilled_Shaft|EPG 751.50 Standard Detailing Notes G8.4 and G8.5].







REVISION REQUEST 4190

copy only table 490.16.4

Table 940.16.4
Driveway Traffic Category Average Daily Traffic Using Driveway Peak Hour Traffic Using Driveway Width at Right of Way Line With Two-Way Access6 Width at Right of Way Line With Two-Way Access6 Right-Turn Radius for Driveways in Urban Areas (At or below 45 mph Posted Speed) Right-Turn Radius for Driveways in Rural Areas (Greater than 45 mph Posted Speed)
Residential 0 - 100 0 - 10 20 ft.1 - 30 ft.2 NA 10 ft. 25 ft.
Agricultural7 0 - 100 0 - 10 30 ft.1 - 40 ft.2 NA 20 ft. - 30 ft.5 30 ft. - 40 ft.5
Low Volume Commercial/Industrial < 1500 < 150 28 ft.2 - 42 ft.3 20 ft.1 25 ft. 50 ft.
Medium Volume Commercial/Industrial 1,500 - 4,000 150 - 400 42 ft.3 - 54 ft.4 20 ft.1 - 30 ft.2 Design to handle typical large truck that uses the driveway Design to handle typical large truck that uses the driveway
High Volume Commercial/Industrial > 4000 > 400 Determined through a traffic study - normally 42 ft. or greater Generally not applicable Design to handle typical large truck that uses the driveway Design to handle typical large truck that uses the driveway
1 One-lane driveways.
2 Driveway striped for two lanes.
3 Driveway striped for three lanes.
4 Driveway striped for four lanes.
5 Uncurbed radius or taper
6 Larger widths up to 60ft may be allowable when right of way is too narrow to accommodate turning radius or based on engineering judgment.
7 Larger widths up to 60ft may be allowable dependent on the type of agricultural activities and equipment the driveway would be expected to accommodate based on engineering judgement.






REVISION REQUEST 4191

902.4.1 General (MUTCD Section 4D.01)

Support. The features of traffic control signals of interest to road users are the location, design, and meaning of the signal indications. Uniformity in the design features that affect the traffic to be controlled, as set forth in this Manual, is especially important for the safety and efficiency of operations.

Traffic control signals can be operated in pretimed, semi-actuated, or full-actuated modes. For isolated (non-interconnected) signalized locations on rural high-speed highways, full-actuated mode with advance vehicle detection on the high-speed approaches is typically used. These features are designed to reduce the frequency with which the onset of the yellow change interval is displayed when high-speed approaching vehicles are in the “dilemma zone” such that the drivers of these high-speed vehicles find it difficult to decide whether to stop or proceed.

EPG 902.23.1 contains information regarding traffic control signal operation.

Standard. The design and operation of traffic control signals shall take into consideration the needs of all modes of traffic including access and safety.

When a traffic control signal is not in operation, such as before it is placed in service, during seasonal shutdowns, or when it is not desirable to operate the traffic control signal, the signal heads shall be covered, turned, or taken down to clearly indicate that the traffic control signal is not in operation.

If a traffic control signal head is not in operation and has a yellow retroreflective strip along the perimeter of its signal backplate (see the fifth option paragraph of EPG 902.4.6), the signal head, shall be covered. If a cover is placed over a traffic control signal head that is not in operation, the entire signal head, including the signal faces and backplate shall be covered.

Standard. A traffic control signal shall control traffic only at the intersection or midblock location where the signal faces are placed.

Guidance. Midblock crosswalks should not be signalized if they are located within 1,000 feet from the nearest traffic control signal, unless supported by an engineering study or engineering judgment that indicates safe and efficient operation of the closely-spaced traffic control signals can be achieved.

Midblock crosswalks should not be signalized if they are located within 100 feet from side streets or driveways that are controlled by STOP signs or YIELD signs, unless supported by an engineering study or engineering judgment that considers restricting turning movements from the side street or driveway to eliminate conflicts with pedestrian and bicyclist movements.

Engineering judgment should be used to determine the proper phasing and timing for a traffic control signal. Since traffic flows and patterns change, phasing and timing should be reevaluated regularly and updated if needed.

Traffic control signals within ½ mile of one another along a major route or in a network of intersecting major routes should be coordinated, preferably with interconnected controller units. Where traffic control signals that are within ½ mile of one another along a major route have a jurisdictional boundary or a boundary between different signal systems between them, coordination across the boundary should be considered.

Support. Signal coordination need not be maintained between control sections that operate on different cycle lengths.

EPG 902.6.19 and EPG 913.4.9 contain information about coordination of traffic control signals with grade crossing signals.







REVISION REQUEST 4202

236.5.29 License Plate Readers

Automated License Plate Readers (LPRs) and Pan-Tilt-Zoom cameras (PTZs) are an increasingly popular way for law enforcement to better locate vehicles associated with criminal activity. The deployment of these devices on Commission right of way require FHWA approval and shall not create a safety risk for the traveling public or interfere with MoDOT’s ability to maintain and operate the transportation system.

The general process for LPR and PTZ requests is outlined in EPG 941.10.

It is the requesting law enforcement agency’s responsibility to contact MoDOT’s local traffic permit specialist to initiate the permitting process, after approval from Department of Public Safety (DPS) has been received. The local district traffic representative will work with the applicant through the permitting process.

Once the district traffic staff determine the LPRs or PTZs are eligible to be deployed on Commission right of way, the district traffic staff will forward the drafted permit via the permit database to Central Office Right of Way (COROW). CO ROW will then gather the following items to seek FHWA approval:

Once COROW gathers the items listed above, they will include the following items in their submittal to FHWA for approval:

Upon receiving FHWA approval, COROW will upload the FHWA approval documentation in the permit database and notify the district traffic staff they may proceed with issuing the permit. If FHWA does not approve, the permit cannot be issued.








941.10.1 Approval Process

The general process for LPR and PTZ requests are outlined in the LPR Flowchart. Law enforcement agencies must request approval, in writing, for deploying LPRs and PTZs from the Director of the Department of Public Safety. Requests are to be on the law enforcement agency letterhead and emailed to the Department of Public Safety at dpsinfo@dps.mo.gov.

The Department of Public Safety (DPS) provides approval for the use of LPR and PTZ devices. MoDOT only facilitates the administration of work by others on Commission right of way. MoDOT’s permitting process will be followed for the constructability and maintenance of the devices to ensure the safety of the traveling public. If an issue is identified through our normal permitting process and cannot be resolved, a permit for this work will not be issued.

It is the requesting law enforcement agency’s responsibility to contact MoDOT’s local permit specialist to initiate the permitting process, after approval from DPS has been received. Contact information for MoDOT’s local permit specialists can be found using the District Permit Maps.

The local district traffic representative will work with the applicant through the permitting process. The permit request submittal must include:

  • An aerial image, or map, depicting all the individual LPR locations included in the submittal.
  • An aerial image for each LPR location included in the submittal clearly showing where the proposed installation with respect to the roadway and other structures on the right of way.
  • A set of drawings, or plans, showing the hardware and their installation details proposed on the right of way, which must be signed and sealed by a Missouri Professional Engineer (P.E.).
  • This applies to stand alone installations as well as installations on approved existing structures on right of way, such as signal and sign truss uprights.
  • Executing a Roles and Responsibilities document to specifically address the expectations of maintaining the devices being installed.
  • A plan to provide electricity to the equipment as well as retrieving data from the equipment.
  • A traffic control plan for any proposed work on the right of way to notify and guide motorists safely through the activity area.
  • A surety deposit or performance bond to insure satisfactory work, accepted by MoDOT.

A separate permit may be provided for the applicant, or their consultant, to access the right of way to collect information needed to develop a set of plans for installing the devices.







941.10.2 Location

When receiving a request, the district traffic staff will work with the law enforcement agency to determine if there are acceptable locations for the proposed installations off MoDOT right of way. If there are no appropriate locations off of right of way, the district traffic staff will work with the agency to determine if the LPRs and PTZs requested can be deployed on Commission right of way.

LPR and PTZ installations on Commission right of way shall only monitor traffic on MoDOT roadways and shall not be used to monitor off system roadways, such as county, city, or private facilities.

Once the district traffic staff determine the LPRs or PTZs are eligible to be deployed on Commission right of way, the district traffic staff will forward the drafted permit via the permit database to Central Office Right of Way (COROW). See section 236.5.29 for COROW’s review and process for requesting FHWA’s approval.

Upon receiving FHWA approval, COROW will upload the FHWA approval documentation in the permit database and notify the district traffic staff they may proceed with issuing the permit. If FHWA does not approve, the permit cannot be issued.

941.10.2.1 LPR and PTZ Non-Permanent Installations - Speed Enforcement Trailers

The only form of non-permanent structure that LPR and PTZ devices may be deployed on, when placed on Commission right of way, are speed trailers. However, speed trailers shall only be deployed for the primary purpose of speed enforcement and not for the primary purpose of deploying LPR and PTZ devices. When speed trailers are deployed, the electronic speed message must be active and the unit deployed and delineated in accordance with EPG 907.8 Speed Trailers Deployed by Others.

941.10.2.2 LPR and PTZ Permanent Installations

To ensure LPR and PTZ devices do not represent an added risk to the traveling public, there are defined installation locations which are acceptable on Commission right of way. Acceptable installation locations include:

  • Only deployed on the right side of the roadway outside of the shoulder.
  • On MoDOT traffic signal upright poles, except in instances where deployment will interfere with other devices already attached to the pole.
  • On MoDOT overhead sign truss upright poles.
  • On any non-breakaway structure owned by a third party, with the written permission of the third party.
  • On independent support behind barrier (installed and maintained by requesting agency or their LPR vendor) in accordance with the guidance in EPG 941.10.2.2.3.
  • On independent breakaway support that has been crash tested by the LPR vendor and approved by MoDOT. See EPG 941.10.2.2.3 for approved systems.

Locations where LPR and PTZ devices shall not be installed include, but are not limited to:

  • Any installation in the median / left side of a divided highway.
  • Any overhead location.
  • On any existing structure on right of way which has a breakaway design, whether it is owned by the Commission or a third party.
  • Any bridge structure.
  • Any location that already has a device installed.
  • Any location that may interfere with MoDOT's ability to manage the transportation system.

MoDOT does not allow the deployment of LPR and PTZ devices overhead or in the median as these locations would result in increased impact on the safety and mobility of the traveling public when performing installation and maintenance activities. LPR and PTZ devices are not permitted on any existing structure which is designed as a breakaway device on Commission right of way, regardless of ownership, as the addition of these devices could negatively impact the performance and safety of the breakaway structure.

There are three methods identified for deploying LPR and PTZ devices on Commission right of way, all of which must be approved by MoDOT and installed under a MoDOT permit:

  • LPRs and PTZs installed on MoDOT structures.
  • LPRs and PTZs installed on non-MoDOT structures.
  • LPRs and PTZs installed on new stand-alone structures.
941.10.2.2.1 LPRs and PTZs Installed on MoDOT Structures

LPRs and PTZs can be attached to MoDOT’s existing traffic signal upright poles and existing sign truss upright poles upon review and approval by MoDOT.

  • Green Box Indicates Acceptable Mounting Location on a
    Traffic Signal, Red Boxes are Unacceptable Mounting Locations
  • Green Box Indicates Acceptable Mounting Location on an Overhead Sign Truss,
    Red Boxes are Unacceptable Mounting Locations
    • 941.10.2.2.2 LPRs and PTZs Installed on non-MoDOT Structures

    There are some structures that have been permitted on Commission right of way which are owned by other entities, such as structures for weigh station bypass equipment or utility poles. Law enforcement agencies have the option to acquire approval from the owners of the structures to utilize them as supports for their LPR and PTZ devices if they meet the following criteria:

    • The structure must be reviewed and approved by MoDOT for use.
    • Written permission from the owner of the structure must be acquired and supplied to MoDOT.
    • Any structure which is of a breakaway design, such as roadway lighting poles or highway signs, are not acceptable support structures.
    • Installation location criteria listed in EPG 941.10.2.2 also apply to these structures.
    941.10.2.2.3 LPRs and PTZs Installed on New Stand-Alone Structures

    To limit the number of structures on Commission right of way, opportunities to locate the LPRs and PTZs off of right of way is the preferred option, followed by an installation location on an existing structure already on right of way. If it is determined a new stand-alone structure is required to facilitate the LPR and PTZ deployment, the following guidance shall be followed:

    ○ No closer than 200 feet upstream of a traffic control device.
    ○ No closer than 50 feet downstream of a traffic control device.
    • Installation and maintenance access should be via adjacent private property or secondary roadways for divided highway, unless physically impossible.






    REVISION REQUEST 4213

    109.12 only

    The primary purpose of a change order is to document a supplemental change to the contract. The official definition, as stated in Sec 101, is as follows:

    Change Order - A written order from the engineer to the contractor, as authorized by the contract, directing changes in the work as made necessary or desirable by unforeseen conditions or events discovered or occurring during the progress of the work.

    The second most primary purpose of the change order process is to ensure proper authority has been granted before proceeding with revisions in quantities or changes in scope of work, design concept, time or specifications. Changes in scope should be limited to the original intent, purpose and limits (length and width) of the job. In instances where proposed changes in scope go beyond these original job parameters, the change order shall be considered a major change order (Sequence 4). Significant scope changes require the State Construction and Materials Engineer to discuss the requested changes with the Asst. Chief Engineer prior to granting approval.

    Change orders must have approval at all required levels before the work proceeds. Exceptions are granted for routine or minor changes, or emergency revisions for which verbal approval has been granted. In rare cases it may be necessary to proceed with emergency measures without prior approval. In such cases, verbal approval should be sought as soon as practicable. Indicate in the DWR remarks the name of the individual who provided verbal approval. For change orders that provide payment for additional work, all attempts should be made to complete the process promptly so that the contractor can be compensated at the end of the pay period in which the work was performed.

    Design Changes - When the change order is a result of a design change, all appropriate design criteria should be reviewed in coordination with the Transportation Project Manager. If the design criteria cannot be met, a Design Exception is required. See EPG 131.1.4.

    Environmental Change Orders - Any design changes that include disturbance of new areas on the project, or that include any other unplanned environmental impacts, should be reviewed by the Project Manager to determine if a request for environmental services is necessary prior to implementation.

    Job Order Contract Change Orders - Job Order Contracts have unique contract terms that limit spending to a budgeted amount and often include pre-approved time extensions. Reference EPG 147.3.9 Change Order Approvals for additional guidance on administration of change orders for Job Order Contracts.







    131.1.1 When to Complete a Design Exception

    Forms
    ● Design Exception Information Form
    ● Vertical Clearance Design Exception Coordination with SDDCTEA

    A design exception documents design elements of an improvement that vary from general guidance on engineering policy. In most cases, the need for an exception results from an inability to reasonably meet the design criteria. The determination to approve a project design that does not conform to the minimum criteria is to be made only after due consideration is given to all project conditions such as maximum service and safety benefits for the dollar invested, compatibility with adjacent sections of roadway and the probable time before reconstruction of the section due to increased traffic demands or changed conditions.

    An approved exception documents the engineering-based determination that variance from MoDOT’s published engineering policy is necessary and appropriate. It is the primary tool to detail not only the decision itself but also what was considered when the decision was made.

    When there is doubt whether a design exception is required, the Assistant State Design Engineers, Assistant State Bridge Engineer, Structural Liaison Engineer (SLE), or the Design Liaison Engineer (DLE) for the district should be consulted.

    A design exception is encouraged whenever it is feasibly or technically impossible to reasonably meet the minimum design criteria or wherever there is potential for additional value outside of written engineering policy. Design exceptions should not be considered breaches of policy as much as opportunities to add practicality or value to the design.

    An approved exception is not a request for permission; rather, it simply documents deliberate variances from general engineering policy. The Federal Highway Administration (FHWA) Design Decision Documentation and Mitigation Strategies for Design Exceptions may be used in the development of the design exception.

    131.1.2 The 10 Controlling Criteria

    There are 10 controlling criteria that the FHWA has identified as the most important or critical elements for the design of projects on the National Highway System (NHS). FHWA only approves design exceptions for the controlling criteria listed in Table 131.1.2 when it has determined that a project is a Project of Division Interest (PODI) with Design Exception selected.

    The controlling criteria, which vary based upon the type of route and design speed, are described below:

    Table 131.1.2 Controlling Criteria
    NHS with Design Speed > 50 mph NHS with Design Speed < 50 mph Non-NHS
    Design Speed Design Speed (No Controlling Criteria)
    Design Loading Structural Capacity Design Loading Structural Capacity
    Lane Width
    Shoulder Width
    Horizontal Curve Radius
    Superelevation Rate
    Stopping Sight Distance
    Maximum Profile Grade
    Cross Slope
    Vertical Clearance

    A design exception approved only by MoDOT is required for all other non-complying design elements on projects which are designated for federal involvement for design exceptions and for all non-complying design elements on all other projects not designated for federal involvement for design exceptions.

    131.1.3 Approval Requirements

    Table 131.1.3 Design Exception Required Approvals
    Category PODI Designated Controlling Criteria* FHWA MoDOT
    NHS Yes Yes ✓ ✓
    No ✓
    No Yes or No ✓
    Non-NHS Yes or No N/A ✓
    * Applicable Controlling Criteria as indicated in EPG 131.1.2.

    131.1.3.1 Projects of Division Interest (PODI)

    See EPG 123.1.1 FHWA Oversight - National Highway System for information on federal involvement on projects and for the PODI matrix.

    131.1.4 The Design Exception Process

    Requests for design exceptions are submitted when the need first arises; however, they may be submitted at any time and specifically along with the conceptual study, preliminary plan, right of way certification, or final plans. All design exceptions should be approved prior to and submitted with the plans, specifications, and estimate (PS&E). In general, it is best to identify, consider, and execute the design exception as early as practical in the design process. When a design change is required during construction, the Resident Engineer should contact the Transportation Project Manager (TPM). If that design change has elements that do not meet design standards, a design exception is required. The normal design exception process is followed.

    When the need for a design exception has been identified, the TPM, Structural Project Manager (SPM), or consultant representative is responsible for completing the standard Design Exception Information Form. The form must include a detailed description of the rationale for the change and the appropriate supporting documentation to satisfactorily justify the decision and document any mitigation efforts associated with varying from the engineering policy. Previous approval of an item should not be considered approval of the item on any future project. Approval for future projects must be sought on a case-by-case basis.

    Project managers (consultant, transportation or structural) and their design staff should recognize the importance of an open and transparent decision making process while considering the suitability and appropriateness of a given design element that is not consistent with current policies. Since engineering policy is established through a collaborative effort, it is critical to engage all appropriate staff when making the decision not to meet policy. While completing the form, communication with the appropriate staff, including the DLE, a representative of any affected MoDOT division and FHWA (when applicable), is critical to ensure efficient and effective review and approval. For efficient processing and to avoid delays, this communication should occur prior to the formal submittal. Depending upon the item being excepted and the type of project, the appropriate review staff and signatory parties will vary.

    Central Office staff should be consulted and provide review of the draft design exception prior to district approval. Design exceptions involving safety related items (see EPG 131.1.5) should be reviewed by the District Traffic Engineer and/or Highway Safety and Traffic Division prior to district approval. For design-bid-build projects, a final copy of the design exception is saved in eProjects using the appropriate content type: DE Design Exceptions, with all necessary checkboxes for Type of Exception checked. Staff should include any pertinent information in the Comments Section within the eProjects metadata. For design-build projects, approved design exceptions incorporated into the project are saved in the design-build projects SharePoint site in an Approved Design Exceptions folder.

    PODI design exceptions are processed through the DLE for the State Design Engineer and FHWA signatures of approval. The DLE provides the electronic copy of the fully approved design exception back to the TPM for placement in eProjects.

    FHWA reserves the right to audit the design exceptions of any federal aid project regardless of level of oversight.

    131.1.4.1 The Development, Concurrence and Approval Process

    In addition to the applicable process requirements described below, vertical clearance design exceptions on the interstate must also follow the additional requirement described in EPG 131.1.7 Deficient Vertical Clearances on Interstates.

    131.1.4.1.1 Roadway Design Exceptions

    Upon the core team's determination that a design exception is warranted, the following process should be used for design exception submittals relating to roadway items only:

    Conceptual Approval:

    1. The TPM working with the Consultant Project Manager, if applicable, submits the design exception information form and supporting information to the DLE, the District Design Engineer (DDE), FHWA (if applicable) and any other pertinent district and division staff.
    2. The contacted division and district representatives will respond with any necessary comments or concerns, request additional information if necessary or will request an opportunity to meet and discuss the issue.
    3. The TPM works with staff to appropriately address or resolve comments, concerns or objections and finalizes the design exception.
    4. The TPM submits the design exception including all supporting documentation in a single pdf file for signature according to the flowchart below.

    Formal Approval:

    Signatures for approval should be obtained in accordance with the following flowchart:

    alt=Flowchart Start - Need for design exception (DE) identified - Go to Process 1 Process 1 MoDOT TPM (and consultant PM, if applicable) obtain conceptual approval of DE – confer with District, Divisions, and FHWA (if applicable) - Go to Process 2 Process 2 - DE revised based on conceptual approval comments - Go to process 3 Process 3 - DE reviewed by DLE - Go to Decision 1 Decision 1 - Is the project designed by a consultant? - If yes, go to Process 4, If no, go to Process 5 Process 4 - Consultant PM signs DE - Go to Process 5 Process 5 - TPM signs DE - Go to Process 6 Process 6 - DLE signs DE - Go to Process 7 Process 7 - TPM obtains District Engineer Signature - Go to Decision 2 Decision 2 - Is FHWA approval required by EPG 131.1.4? If yes, go to Process 8. If no, go to End. Process 8 - TPM sends DE to DLE - Go to Process 11 Process 9 - DLE obtains State Design Engineer signature - Go to Process 10 Process 10 - DLE obtains FHWA signature - Go to Process 10 Process 11 - DLE returns DE to TPM - Go to End End - TPM stores DE in eProjects
    alt=Flowchart Start - Need for design exception (DE) identified - Go to Process 1 Process 1 MoDOT TPM (and consultant PM, if applicable) obtain conceptual approval of DE – confer with District, Divisions, and FHWA (if applicable) - Go to Process 2 Process 2 - DE revised based on conceptual approval comments - Go to process 3 Process 3 - DE reviewed by DLE - Go to Decision 1 Decision 1 - Is the project designed by a consultant? - If yes, go to Process 4, If no, go to Process 5 Process 4 - Consultant PM signs DE - Go to Process 5 Process 5 - TPM signs DE - Go to Process 6 Process 6 - DLE signs DE - Go to Process 7 Process 7 - TPM obtains District Engineer Signature - Go to Decision 2 Decision 2 - Is FHWA approval required by EPG 131.1.4? If yes, go to Process 8. If no, go to End. Process 8 - TPM sends DE to DLE - Go to Process 11 Process 9 - DLE obtains State Design Engineer signature - Go to Process 10 Process 10 - DLE obtains FHWA signature - Go to Process 10 Process 11 - DLE returns DE to TPM - Go to End End - TPM stores DE in eProjects


    131.1.4.1.2 Bridge Design Exceptions

    The following process should be used for design exception submittals relating to bridge items:

    Conceptual Approval:

    1. The SPM, or the SLE working with the Consultant Project Manager submits the design exception form to the Assistant State Bridge Engineer, the DLE, the Transportation Project Manager, FHWA (if applicable) and any other pertinent district and division staff.
    2. The contacted division and district representatives will respond with any necessary comments or concerns, request additional information if necessary or will request an opportunity to meet and discuss the issue (if significant objection is determined).
    3. The SPM/SLE works with staff to appropriately address or resolve comments, concerns or objections and finalizes the design exception.
    4. The SPM/SLE submits the design exception including all supporting documentation in a single pdf file for signature according to the flowchart below.

    Formal Approval:

    Signatures for approval should be obtained in accordance with the following flowchart:

    alt=Flowchart Start - Need for design exception (DE) identified - Go to Process 1 Process 1 MoDOT TPM (and consultant PM, if applicable) obtain conceptual approval of DE – confer with District, Divisions, and FHWA (if applicable) - Go to Process 2 Process 2 - DE revised based on conceptual approval comments - Go to process 3 Process 3 - DE reviewed by DLE - Go to Decision 1 Decision 1 - Is the project designed by a consultant? - If yes, go to Process 4. If no, go to Process 5 Process 4 - Consultant PM signs DE - Go to Process 5 Process 5 - TPM signs DE - Go to Process 6 Process 6 - DLE signs DE - Go to Process 7 Process 7 - SLE/SPM signs DE - Go to Process 8 Process 8 - State Bridge Engineer signs DE - Go to Process 9 Process 9 - TPM obtains District Engineer Signature - Go to Decision 2 Decision 2 - Is FHWA approval required by EPG 131.1.4? If yes, go to Process 10. If no, go to End. Process 10 - TPM sends DE to DLE - Go to Process 11 Process 11 - DLE obtains State Design Engineer signature - Go to Process 12 Process 12 - DLE obtains FHWA signature - Go to Process 13 Process 13 - DLE returns DE to TPM - Go to End End - TPM stores DE in eProjects
    alt=Flowchart Start - Need for design exception (DE) identified - Go to Process 1 Process 1 MoDOT TPM (and consultant PM, if applicable) obtain conceptual approval of DE – confer with District, Divisions, and FHWA (if applicable) - Go to Process 2 Process 2 - DE revised based on conceptual approval comments - Go to process 3 Process 3 - DE reviewed by DLE - Go to Decision 1 Decision 1 - Is the project designed by a consultant? - If yes, go to Process 4. If no, go to Process 5 Process 4 - Consultant PM signs DE - Go to Process 5 Process 5 - TPM signs DE - Go to Process 6 Process 6 - DLE signs DE - Go to Process 7 Process 7 - SLE/SPM signs DE - Go to Process 8 Process 8 - State Bridge Engineer signs DE - Go to Process 9 Process 9 - TPM obtains District Engineer Signature - Go to Decision 2 Decision 2 - Is FHWA approval required by EPG 131.1.4? If yes, go to Process 10. If no, go to End. Process 10 - TPM sends DE to DLE - Go to Process 11 Process 11 - DLE obtains State Design Engineer signature - Go to Process 12 Process 12 - DLE obtains FHWA signature - Go to Process 13 Process 13 - DLE returns DE to TPM - Go to End End - TPM stores DE in eProjects

    131.1.4.1.3 Both Roadway and Bridge Item Related Design Exceptions

    Occasionally, both roadway and bridge items will need to be included. In these instances, the TPM and the SLE/SPM should agree to a single point of contact for the review, concurrence and approval of the design exception and will ensure that the appropriate staff members are properly engaged throughout the process.

    131.1.4.2 Issue Resolution

    The review and concurrence process is intended to avoid any significant objections, questions or concerns during the approval process, however, occasionally these issues may arise. In this instance, the design exception approval process may be put on hold until the issue can be resolved by the appropriate staff members. The TPM or SLE/SPM will remain the primary contact to address any request for additional information or consideration.

    131.1.5 Completing the Design Exception Information Form

    Whenever engineering policy cannot be met, data for only those non-standard items is listed on the form. This data includes a brief description of the project and the improvement goals that are being attempted. This information is required since the context of the project often helps in deciding if approval of the exception is appropriate. Additionally, the data should include the details related to the location (limits) associated with the solution, the existing condition (if applicable), the standard design criteria for that feature, and the proposed design solution. The column shown for the existing condition is not applicable to new construction. The appropriate values for desired design criteria are shown in the third column. The design criteria for new construction on rural and urban highways are stated in individual articles pertaining to each geometric element discussed in the EPG 200 Geometrics articles. Design criteria for 3R and 4R projects are discussed in EPG 128 Conceptual Studies. The criteria for proper access management can be found in EPG 940 Access Management.

    All design exceptions must suitably explain the justification for the exception. It is imperative that this justification be sufficiently complete to clearly reflect that the designer exercised reasonable care in the selection of a particular highway design. Design exceptions often arise because it is impractical or impossible to reasonably meet engineering policy. The justification may include appropriate economic analysis, discussion of applicable accident location and type or discussion of avoidance of Section 4(f) or Section 6(f) lands. The justification supports the concept that maximum service and safety benefits were realized for the cost invested. Engineering judgment is used when balancing the economic and engineering reasons for the justification. A design exception is based on sound engineering judgment rather than being solely an attempt to save cost.

    In general all design exceptions should include the following:

    • Specific design criteria that will not be met.
    • Existing roadway characteristics.
    • Alternatives considered.
    • Comparison of the safety and operational performance of the roadway and other impacts such as right-of-way, community, environmental, cost, and usability by all modes of transportation.
    • Proposed mitigation measures.
    • Compatibility with adjacent sections of roadway.

    Note: The level of analysis should be commensurate with the complexity of the project.

    In addition to the information above, exceptions for the Design Speed and Design Loading Structural Capacity criteria should include the following information;

    Design Speed exceptions:
    • Length of section with reduced design speed compared to overall length of project
    • Measures used in transitions to adjacent sections with higher or lower design or operating speeds.
    Design Loading Structural Capacity exceptions:
    • Verification of safe load-carrying capacity (load rating) for all state unrestricted legal loads or routine permit loads, and in the case of bridges and tunnels on the interstate, all federal legal loads.

    For design exceptions related to existing conditions, a review of the existing condition crash history is required. The review should focus on crash types to which the design element may relate with a special consideration to fatal and injury crashes. A summary report of the crash information is acceptable if the volume of the data is excessive. Specific attention should be paid to design elements that have a direct impact on safety. Examples of such design elements include, but are not limited to, the following: design speed, stopping sight distance, passing sight distance, lane width, shoulder width, shoulder type, rumble strips, turn lanes, access management requirements, bridge approach rail, horizontal alignment, vertical alignment, grade, horizontal clearance, vertical clearance, guardrail, etc.

    In addition, if the design exception request involves safety related features that are adequately addressed in the AASHTO Highway Safety Manual, then documentation of the exception should include a safety analysis as described in the manual. Typically, this process will involve two primary determinations:

    • Calculate the expected change in crashes from existing conditions to standard design conditions.
    • Calculate the expected change in crashes from existing conditions to the proposed design.

    The proposed design should take into account any design exceptions as well as any additional safety features above and beyond the standard design.

    By making these two determinations, a quantitative safety comparison can be made between existing conditions, the standard design, and the proposed design. This information, along with other project considerations, can be used to help determine the best design alternative. A list of features currently addressed by the manual include: lane width, shoulder width, shoulder type, center line rumble strips, horizontal alignment (length, radius), grade, roadside hazard rating, fixed objects, driveway density, median width, sideslope, lighting, intersection skew angle and turn lanes. Not all features in the manual are addressed for every facility type. If a feature is not addressed in the manual, a statement should be included on the design exception stating that fact. For features not addressed in the HSM, a qualitative discussion may be included.

    131.1.6 Revising an Approved Design Exception

    Changes in project scope or design criteria can result in changes to design exceptions that have previously been approved. In these cases, a revised design exception must be completed and approved (as described above). The reasoning on revised design exceptions should address the changes and an explanation of the circumstances leading to the revision. The original design exception should accompany the revised information in order to illustrate the changes.

    131.1.7 Deficient Vertical Clearances on Interstates

    Maintaining the integrity of interstates for national defense purposes has long been recognized. Interstates are intended to be constructed and maintained to meet AASHTO Policy as stated in A Policy on Design Standards - Interstate System, which is incorporated by reference in 23 CFR 625. Maintaining standard vertical clearances to the extent possible for defense mobilization is considered particularly important and is a focus at the national level. As a result, the FHWA has agreed that all exceptions to a 16 foot (16') vertical clearance standard for the rural Interstate routes or on a single routhe through urban areas must be coordinated with the Surface Deployment and Distribution Command Transportation Engineering Agency (SDDCTEA) of the Department of Defense. This coordination applies whether it is a new construction project, a project that does not provide for the correction of an existing substandard condition, or a project that creates a substandard condition at an existing structure. The steps involved are:

    1. For a vertical clearance over any interstate highway that will be less than 16 ft. meeting the above criteria, the district submits to the Design Division a completed SDDCTEA Interstate Vertical Clearance Coordination Form along with a Design Exception for vertical clearance.
    2. The DLE emails the Bridge Inventory Analysts and requests the Structure NBI number for box 2 on the Vertical Clearance Design Exception Coordination with SDDCTEA Form.
    3. Concurrent with the submission or routing of the Design Exception, the DLE submits the SDDCTEA Form to the SDDCTEA and copies FHWA. This may be done electronically using the contact information on the Vertical Clearance Design Exception Coordination with SDDCTEA.
    4. A response from SDDCTEA should occur within 10 working days following receipt of the coordination request. Receipt of the request can be verified with SDDCTEA via telephone, fax, or email. If there is no response after 10 working days following receipt, it can be determined that SDDCTEA does not have any concerns about the proposed exception.
    5. The DLE informs FHWA as to the final outcome of the SDDCTEA request.

    REMOVED CAT LINK!!!!''''Bold text'REMOVED CAT LINK!!!!Big text






    REVISION REQUEST 4220

    751.8.1.5 Precast Culvert

    General

    All MoDOT cast-in-place (CIP) concrete box culverts are allowed to be constructed using alternate precast concrete box culvert sections in accordance with Sec 733, unless specified otherwise. Requirements for submitting special or modified designs are described in Sec 1049. Precast split-box designs in accordance with ASTM C1786 with or without modification are not an acceptable precast alternative.The converse is not true and precast concrete box culverts may be specified only. Pay items and quantities shall remain unchanged from those typically used for CIP concrete box culverts. When a box culvert is required to be constructed using precast concrete box culvert sections because of an accelerated timeline for construction, pay item and quantity of the precast box culvert shall be based on the length of the precast culvert to the nearest foot measured along the geometrical center of the culvert floor.

    Pedestrian Box

    Where a precast concrete box culvert could be used as a pedestrian (or “people”) box for walk-through or bicycle path, having multiple joints typically spaced at not greater than 6 ft. may be unacceptable due to tripping hazards, ponding/freezing (settlement of many smaller length sections) or uncomfortable riding surface. Consideration should also be given to special waterproofing or non-corrosive water stops for watertight construction joints.

    Multi-Cells

    In multi-cell precast construction the staggered placement of units should be avoided. Staggering units results in an irregular end section that loses continuity over the interior wall(s).

    Culvert Ties

    Precast box culvert ties in accordance with Sec 733 and Std. Plan 733.00 shall be required for the same reasons as concrete collars are required for CIP concrete box culverts. Typically the regular strength connections details should be used. The extra strength connection details shall be used for special cases requiring higher strengths or greater durability, for example when connecting energy dissipating baffles rings or when under low fills and a roadway. If a precast box culvert is required because of an accelerated timeline and collar beams would otherwise be required then culvert ties shall be specified with the cost of ties being considered completely covered by the contract unit price for the precast box culvert.






    1049.2 Procedure

    Inspection and reporting of coarse aggregate, fine aggregate, cement, fly ash shall be as appropriate for those materials.

    Prior to concrete being poured, confirm the amount and placement of reinforcement. The amount and placement of welded wire fabric is to be as specified in ASTM C 1577 as applicable.

    Compressive tests may be made on either concrete cylinders or cores drilled from the wall of the sections at the option of the manufacturer. If the manufacturer chooses to take cylinders and they fail, the manufacturer then has the option to core sections for possible acceptance.

    Cylinders must be made in accordance with AASHTO T 280 and must be capped.

    Acceptance cylinders are the responsibility of the manufacturer. An inspector’s job is to review the results for adequacy. It is good procedure to randomly validate the manufacturer results by making cylinders for comparison.

    Cores in accordance with AASHTO T 280 must be both capped and lime cured.

    The finished sections are to be examined for conformance to dimensions, workmanship and marking. All permissible variations are specified in ASTM C 1577.

    Each section shall be marked as follows by the manufacturer by indenting into the concrete or with waterproof paint:

    (a) Box section span, rise, table number, design earth cover and specification designation.
    (b) Date of manufacture.
    (c) Name or trademark of the manufacturer.
    (d) Each section shall be clearly marked by indentation on either the inner or outer surface during the process of manufacturer so that the location of the top will be evident immediately after the forms are stripped. In addition, the word "top" shall be lettered with waterproof paint on the inside top surface.
    (e) If the manufacturer is allowed to produce under an approved QC program, each section considered by the manufacturer to be specification compliant will be marked by the manufacturer with the indicator required by the QC program. Sections rejected by the manufacturer may be marked or handled in accordance with the QC program but the rejection must be clearly indicated.
    (f) If the manufacturer is allowed to produce under an approved QC program, each section to be shipped will be marked by the manufacturer with the Sample ID number provided by the district. If the producer has marked a piece with a Sample ID number, and the section is found to be unacceptable during an audit, the Sample ID number must be neatly obliterated.

    Sections accepted by MoDOT inspection are to be marked with "OK-MoDOT" by the inspector. Rejected sections are to be marked with a single vertical mark, near the manufacturers marking and shall be made with weather resistant marking material.

    Any modification of a unit, other than constructing a box unit exactly as described in the specifications, is considered a special design, including any pipe cutouts or drainage holes to be made in the unit for any reason, whether prior to, during, or after final placement on site. Any special or modified designs submitted for approval must have been reviewed and sealed by a professional engineer, registered in Missouri, and representing the contractor or producer. Requirements for submitting special or modified designs are described in Sec 1049. Precast split-box designs in accordance with ASTM C1786 with or without modification are not an acceptable precast alternative. Approval of a special design for one job does not constitute approval for any other job.

    Submittal of special designs is discussed further in EPG 106.16 Special Designs. Special and modified design units, at the discretion of the district, may not be accepted under a QC program.

    If reinforcing bars are proposed in lieu of the welded wire fabric listed in AASHTO, it is considered to be a special design.

    If end sections are proposed to be constructed other than by the MoDOT Standard Plans for cast-in-place culverts, it is considered to be a special design. Calculations and other proof of equal or better design must be submitted with the request.






    Retrieved from "https://epg.modot.org/index.php?title=User_talk:Hoskir&oldid=58703"