902.4 Signal Installations and Equipment
902.10.1 New Signal Installations
After it has been identified that signals are needed at an intersection, it will be necessary to pursue funding for the installation. The type of installation and the source of funding will depend on many factors. It is usually necessary to develop a priority list of intersections, since funding is not available to signalize every intersection that meets signal warrants. District Traffic is consulted for recommendations concerning the signal control type before design of the preliminary signal layout is started.
902.10.1.1 Permanent Signals. Permanent signals are installations using steel mast arm poles, underground conduit and basic intersection lighting. The signals, lighting and intersection geometrics are constructed according to current Design standards. Permanent signals are typically installed with construction projects or at locations where there are no programmed major roadway projects that would affect the signals.
902.10.1.2 Span Wire Signals. Span wire signals are installed with wood or steel span wire poles and overhead wiring. Span wire signals are constructed with adequate geometrics for efficient operation but the geometrics may not be up to full Design standards. Span Wire signals are to be installed with basic lighting on the signal poles (silhouette lighting) unless other basic lighting is in place. Span wire signals may be installed by contract, by department forces or a combination of the two.
Span wire signals are typically installed where signals are needed sooner than permanent signals can be programmed. This may occur where there is a future construction project that will install signals or where there is no work currently programmed. If no work is programmed, it is advantageous to pursue the programming of a permanent signal installation to replace the span wire signals.
902.10.1.3 Right of Way and Construction Funding. The installation of permanent signals may be funded by right of way and construction funds. For new construction or programmed major improvements, intersections that are currently signalized or meet warrants for signals are to have permanent signals included in the design. If no improvements are programmed, it may be possible to program permanent signal installations. Contact district Design or Planning for information on status of programmed projects or the possibility of programming signals. In some cases, signals may be installed on a high hazard project that is also part of the right of way and construction program.
902.10.1.4 Traffic or District Funding. It may become necessary to install signals prior to the time they can be provided through the normal Right of Way and Construction Program. Intersections that satisfy the warrants described in 902.2, Warrants for Traffic Signal Installation, may qualify for the installation of signals with Central Office or district funds.
902.10.1.4.1 Submittals and Documentation. If the district plans to install a signal totally with district funds, Traffic needs to be advised with information on the location and type of signal being installed, expected time of implementation and a statement that all other pertinent documentation is on file in the district.
If Central Office funds are being requested for the installation, a request to install signals and minor geometrics, if needed is to be submitted to Traffic. The request is to contain information on location and type of signals, warrant(s) met, stock controller request (if needed), estimated cost, expected time of implementation and a statement that all other pertinent documentation is on file in the district. For all district and Central Office funded signal installations, the district needs to document and keep on file volume counts, an explanation of warrants met, on-site photographs, a sketch of the intersection, proposed signal indications and phasing diagrams, estimated cost, the name of the political subdivision in whose jurisdiction the signal is to be installed and any other studies or information that pertains to the signal installation.
902.10.1.4.2 Central Office Funding Limitations. Central Office funds are limited and districts will compete for funding. If more than one project is requested by a district, that district is to prioritize its submittals. Due to budget constraints, it may be necessary to cut projects or fund only a percentage of the project cost. These funds are intended for low cost signal installations requiring no geometric revisions or minor geometric revisions. Typically, no more than $35,000 is funded for signals and no more than $100,000 is funded for signals with minor geometrics. For work done by department forces, only the cost of materials and equipment usage can be funded. All contract costs can be funded on contract installations. For contract installations, equipment may be provided by the department or by the contractor.
902.10.1.4.3 Central Office Funding – Types of Signals. Central Office funds are intended for span wire signal installations requiring no geometric revisions or minor geometric revisions. Wood pole span wire signals are recommended for installations that will be in place for less than 10 years. Steel pole span wire signals are recommended for installations that will be in place for more than 10 years. These funds may be used for permanent mast arm signals but only a portion of the cost of the permanent signals is typically funded. Only minor geometric revisions with permanent signals can typically be funded with Central Office funds.
902.10.1.4.4 Funds Reimbursement. Central Office funds approved for projects are reimbursed to the district by transferred funds. When an installation contract is executed or when an installation by department forces is completed, the district may request a transfer of funds. This request includes a copy of any executed contracts or purchase orders. Where work is done by department forces, a detailed listing of material and equipment costs is needed. The request is to also indicate the AFE to transfer funds to.
902.10.1.5 Developing Contracts for Signal Installations. Signal installations and any associated geometrics may be contracted in part or completely. Proper procedures need to be followed in developing and letting contracts.
902.10.1.5.1 Contract Work $25,000 or Less. Smaller contracts may be developed by obtaining quotes. An approved request for quotation form is used to get quotes from appropriate bidders for the work needed. Bonding and advertising are not required for these quotes. The following are required:
1. An engineer’s estimate is required before the request for quotation is sent.
2. Prevailing wage is required if the work is construction, reconstruction, improvement, enlargement, alteration, painting or major repair.
3. The request for quotation is sent to as many appropriate bidders as practical. A minimum of three quotes are needed when possible.
4. Quotes are approved at the district level by a District Traffic Engineer, Operational Support Engineer, or higher.
5. The district can approve or reject quotes up to 20% above the $25,000 limit, provided they are reasonably close to the engineer’s estimate. Any quote more than 20% over the $10,000 limit will require Central Office approval.
902.10.1.5.2 Contract Work Above $25,000. District Design and district Traffic is to work together to prepare traffic roadway and signal contracts. These contracts shall be developed and let following the latest revision of the District Bid Opening Procedures from Design.
902.10.1.6 Signal Installations by Others. The policies for school flashers and signals, fire station signals, and other special signal installations are covered in 902.4, Flashers and Signals for Schools and Other Special Applications.
902.10.2 Controllers and Equipment
902.10.2.1 Controller Replacement Program. When possible, Traffic Division maintains funding for routine replacement of signal controllers. This program helps to maintain reliable control equipment for traffic signals. Typically, controller assemblies 14 years or older are replaced or as funding allows. In addition, controller assemblies that have higher than normal maintenance problems and obsolete equipment that is difficult to obtain parts for are eligible to be replaced.
The districts develop a list of needs by age based on information in the signal inventory. This list can be developed by running two TMS queries: Traffic Signal Inventory by Age of Controller and Traffic Signal Inventory by Age of Cabinet. The following steps will access both queries in TMS: Start - TMS - Queries and Reports - Query Selection - Traffic/Congestion Reports - Inventory Reports - Traffic Signal Inventory by Age of Controller or Traffic Signal Inventory by Age of Cabinet. The districts will review the reports developed from the two queries and propose any additional controllers or delete locations from the lists that are scheduled for construction contracts or other means of replacement. For controller assemblies added, due to high maintenance or obsolete equipment, the district submits maintenance records or other documentation to back up the request. Upon review and approval of the requests, Traffic Division will notify the districts of approved replacement locations. The districts prepare order forms for controller assemblies and submit timing and phasing sheets electronically to Traffic Division. It is important to be very specific on controller order forms so that correct equipment is received. Figure 11.1 shows an example for filling out controller order forms for NEMA's and 170's. All replacement units are bid at the same time to help reduce overall costs. Additional controller assembly purchases desired by the district can also be made with the replacement program to help reduce purchase costs. These additional purchases would be funded with district funds.
Upon receipt of replacement equipment, the districts are to inspect the units received for conformance to specifications and purchase order requirements. If problems are found, the district is to notify the vendor as soon as possible. The purchase specifications spell out conditions for acceptance and testing. A test period is required prior to acceptance. It is most desirable to set up controllers for testing on a board in the shop, but if controllers are needed immediately, they may be tested in the field. For large orders, as many units as possible are to be tested, but it is not required to test every unit.
902.10.2.2 Stock Controllers. When possible, Traffic Division maintains a stock of signal controllers. The purpose of these controllers is for quick replacement of controllers destroyed by crashes, lightning, etc. and for new signal installations at warranted locations using Traffic Division or district funding. For emergency replacements, the district may contact Traffic Division for a stock controller. Arrangements will be made for the quickest possible delivery, or the district may pick up the controller at Central Office. The district then follows up with a Lotus Notes request with an explanation of the date and nature of the incident that destroyed the controller. For new signal installations, the request is to be accompanied by information on the location and type of signal being installed, warrant(s) met, expected time of implementation and a statement that all other pertinent documentation is on file in the district. See 902.10.1.4.1, Submittals and Documentations, for information on other required documentation. For all stock controller requests, the type of controller being requested is indicated with the note "From Traffic Division Stock". Consideration may also be given to purchasing stock Type 170 controllers for the districts currently using them. These Type 170 stock controllers are typically purchased with the controller replacement program.
It will be necessary for districts to perform the acceptance test period for stock controllers since Central Office does not have facilities to test controllers. The districts receiving the first few stock controllers from a new delivery will be asked to perform the acceptance test period.
902.10.2.3 Crash Damage to Controllers. Occasionally a crash will result in the destruction of a signal controller. Whenever this occurs, MoDOT tries to collect for the damages incurred. The following depreciation schedule shall be applied when determining the present worth of an existing controller that has been damaged.
| Age, In Years | Worth, % of Original Value |
|---|---|
| 0-1 | 100 |
| 1-2 | 99 |
| 2-3 | 98 |
| 3-4 | 96 |
| 4-5 | 93 |
| 5-6 | 89 |
| 6-7 | 85 |
| 7-8 | 80 |
| 8-9 | 74 |
| 9-10 | 67 |
| 10-11 | 60 |
| 11-12 | 52 |
| 12-13 | 43 |
| 13-14 | 33 |
| 14-15 | 23 |
| 15-16 | 12 |
| 16 or More | 2 |
902.10.2.4 Crash Damage to Signal Heads and Supports. Whenever damages occur to signal heads and their supports, collection for damages shall also be attempted. Straight line depreciation shall be used with a 15-year life used for all signal heads and all temporary span wire supports and a 25-year life used for all permanent supports.
902.10.2.5 Approved Products Lists and Equipment Evaluations. MoDOT has developed an Approved Products List (APL) containing many items used in signals and lighting. The APL is based on equipment that meets department specifications and has been tested for a specified test period with satisfactory performance. This list helps MoDOT purchase reliable products for traffic signals and highway lighting. This list is included in the bid requests for applicable equipment purchases and is also included in construction contracts that include signals or lighting.
MoDOT frequently tests new products and equipment for signals. These new products may be installed on a construction project, purchased on parts orders or with controller orders. Only a limited number of units will be accepted for test statewide until an item is added to the approved products list.
All equipment evaluations are coordinated through Traffic and are typically reviewed by the Traffic Signal Quality Circle. The vendor supplying the equipment must provide equipment specifications and a certification that the equipment meets MoDOT specifications before the test is performed. The equipment is tested for the period specified on the approved products list. Products that are not performing satisfactorily may be replaced at any time if the vendor cannot provide timely correction of the problem or if unsatisfactory operation of the intersection results. Upon completion of the test, the district completes an Equipment Evaluation Form for Signal and Lighting Equipment and submits it to Traffic. The evaluation is reviewed by the Traffic Signal Quality Circle for addition to the APL or for rejection.
If a vendor is proposing a product that does not meet department specifications, the vendor must provide a written explanation to Traffic of why the product meets or exceeds the current specifications. If approved, the product may be tested for the specified period as described above. If the product is satisfactory, Traffic will consider making a recommendation to revise the applicable specifications. Products that do not meet specifications will not be added to the approved products list.
902.10.2.6 Experimental Equipment. MoDOT often evaluates experimental equipment for traffic signals. Experimental equipment may be new products or products that vary considerably from our current standards or practices. The evaluation of experimental products may be initiated by district or Central Office staff, as part of a research project, as an implementation of an employee idea, etc.
The evaluation of experimental equipment for traffic signals is coordinated through Traffic and may involve other functional units such as Research, Development and Technology. If the evaluation is part of a research project, then the project will provide guidelines for testing. Products may be evaluated in a similar manner to that described in 902.10.2.5. Before evaluating experimental equipment, it is important to address all issues. Some items to consider are as follows:
- What improvement will the equipment provide?
- Does the equipment conform to National and State standards?
- Is the equipment cost effective?
- Are funds available?
- What are the advantages and disadvantages of the equipment?
- How will the effectiveness of the equipment be tracked?
- What criteria will be used to determine if the equipment is satisfactory?
Equipment Evaluation Form for Signal and Lighting Equipment can be used for evaluation of experimental equipment.
902.10.2.7 Annual Orders and District Signal and Lighting Equipment Purchases. Traffic Division will coordinate annual orders for signal and lighting equipment purchases.
The intent of annual orders is to combine orders from all districts to develop larger quantities and to save duplication of work. Annual orders are limited to items that will be purchased in larger quantities and can be bid competitively. For signal and lighting annual orders, it is important that only these types of items be included in the requests.
Proprietary items, model specific replacement parts, and small quantity items are to be purchased at the district level. In addition, there are many common "off-the-shelf" items that can be purchased at local suppliers, saving time, and in many cases money. Traffic staff may ask the districts to order some items from annual orders on their own if it does not appear they will benefit from the annual order process.
District purchases is to follow General Service’s guidelines for purchasing. Some items that may need to be included in equipment bids are as follows:
- Reference to the Standard Specifications (if applicable). Indicate the exact section that applies.
- Reference to the approved products list (if applicable). Include a copy of the current list.
- Supplemental specifications (if applicable). Include a copy of the specifications. An example is signal controller purchases. Traffic maintains supplemental purchase specifications for controllers and other items.
