903.20 Signing for Rail and Light Rail Transit Grade Crossings

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903.17 Highway-Rail Grade Crossings.jpg

903.17.1 Introduction (MUTCD Section 8A.01)

Support. Traffic control for highway-rail grade crossings includes all signs, signals, markings, other warning devices and their supports along highways approaching and at highway-rail grade crossings. The function of this traffic control is to permit reasonably safe and efficient operation of both rail and highway traffic at highway-rail grade crossings.

For purposes of installation, operation, and maintenance of traffic control devices at highway-rail grade crossings, it is recognized that the crossing of the highway and rail tracks is situated on a right of way available for the joint use of both highway traffic and railroad traffic.

The highway agency or authority with jurisdiction and the regulatory agency with statutory authority, if applicable, jointly determine the need and selection of devices at a highway-rail grade crossing.

In Traffic Controls for Highway-Rail Grade Crossings, the combination of devices selected or installed at a specific highway-rail grade crossing is referred to as a “traffic control system.”

Standard. The traffic control devices, systems and practices described herein shall be used at all highway-rail grade crossings open to public travel, consistent with federal, state and local laws and regulations.

To promote an understanding of common terminology between highway and railroad signaling issues, the following definitions shall be used:

1. Advance Preemption—the notification of an approaching train that is forwarded to the highway traffic signal controller unit or assembly by the railroad equipment in advance of the activation of the railroad warning devices.

2. Advance Preemption Time—the period of time that is the difference between the required maximum highway traffic signal preemption time and the activation of the railroad warning devices.

3. Cantilevered Signal Structure—a structure that is rigidly attached to a vertical pole and is used to provide overhead support of signal units.

4. Clear Storage Distance—the distance available for vehicle storage measured between 6 ft. from the rail nearest the intersection to the intersection stop line or the normal stopping point on the highway. At skewed highway-rail grade crossings and intersections, the 6 ft. distance shall be measured perpendicular to the nearest rail either along the centerline or edge line of the highway, as appropriate, to obtain the shorter distance. Where exit gates are used, the distance available for vehicle storage is measured from the point where the rear of the vehicle would be clear of the exit gate arm. In cases where the exit gate arm is parallel to the track(s) and is not perpendicular to the highway, the distance is measured either along the centerline or edge line of the highway, as appropriate, to obtain the shorter distance.

5. Design Vehicle—the longest vehicle permitted by statute of the road authority (state or other) on that roadway.

6. Dynamic Envelope—the clearance required for the train and its cargo overhang due to any combination of loading, lateral motion, or suspension failure (see Figure 903.17.1).

7. Dynamic Exit Gate Operating Mode—a mode of operation where the exit gate operation is based on the presence of vehicles within the minimum track clearance distance.

8. Exit Gate Clearance Time—for Four-Quadrant Gate systems, the exit gate clearance time is the amount of time provided to delay the descent of the exit gate arm(s) after entrance gate arm(s) begin to descend.

9. Exit Gate Operating Mode—for Four-Quadrant Gate systems, the mode of control used to govern the operation of the exit gate arms.

10. Flashing-Light Signals—a warning device consisting of two red signal indications arranged horizontally that are activated to flash alternately when a train is approaching or present at a highway-rail grade crossing.

Active Warning System

11. Interconnection—the electrical connection between the railroad active warning system and the highway traffic signal controller assembly for the purpose of preemption.

12. Maximum Highway Traffic Signal Preemption Time—the maximum amount of time needed following initiation of the preemption sequence for the highway traffic signals to complete the timing of the right-of-way transfer time, queue clearance time, and separation time.

13. Minimum Track Clearance Distance—for standard two-quadrant railroad warning devices, the minimum track clearance distance is the length along a highway at one or more railroad tracks, measured either from the highway stop line, warning device, or 12 ft. perpendicular to the track centerline, to 6 ft. beyond the track(s) measured perpendicular to the far rail, along the centerline or edge line of the highway, as appropriate, to obtain the longer distance. For Four-Quadrant Gate systems, the minimum track clearance distance is the length along a highway at one or more railroad tracks, measured either from the highway stop line or entrance warning device, to the point where the rear of the vehicle would be clear of the exit gate arm. In cases where the exit gate arm is parallel to the track(s) and is not perpendicular to the highway, the distance is measured either along the centerline or edge of the highway, as appropriate, to obtain the longer distance.

14. Minimum Warning Time—Through Train Movements—the least amount of time active warning devices shall operate prior to the arrival of a train at a highway-rail grade crossing.

15. Preemption—the transfer of normal operation of highway traffic signals to a special control mode.

16. Pre-signal—supplemental highway traffic signal faces operated as part of the highway intersection traffic signals, located in a position that controls traffic approaching the highway-rail grade crossing in advance of the intersection.

17. Queue Clearance Time—the time required for the design vehicle of maximum length stopped just inside the minimum track clearance distance to start up and move through and clear the entire minimum track clearance distance. If presignals are present, this time shall be long enough to allow the vehicle to move through the intersection, or to clear the tracks if there is sufficient clear storage distance. If a Four-Quadrant Gate system is present, this time shall be long enough to permit the exit gate arm to lower after the design vehicle is clear of the minimum track clearance distance.

18. Right-of-Way Transfer Time—the maximum amount of time needed for the worst case condition, prior to display of the track clearance green interval. This includes any railroad or highway traffic signal control equipment time to react to a preemption call, and any traffic control signal green, pedestrian walk and clearance, yellow change, and red clearance intervals for conflicting traffic.

19. Separation Time—the component of maximum highway traffic signal preemption time during which the minimum track clearance distance is clear of vehicular traffic prior to the arrival of the train.

20. Simultaneous Preemption—notification of an approaching train is forwarded to the highway traffic signal controller unit or assembly and railroad active warning devices at the same time.

21. Timed Exit Gate Operating Mode—a mode of operation where the exit gate descent is based on a predetermined time interval.

22. Vehicle Intrusion Detection Devices—a detector or detectors used as a part of a system incorporating processing logic to detect the presence of vehicles within the minimum track clearance distance and to control the operation of the exit gates.

23. Wayside Equipment—the signals, switches, and/or control devices for railroad operations housed within one or more enclosures located along the railroad right-of-way and/or on railroad property.

903.17.2 Use of Standard Devices, Systems and Practices (MUTCD Section 8A.02)

Support. Because of the large number of significant variables to be considered, no single standard system of traffic control devices is universally applicable for all highway-rail grade crossings.

Guidance. The appropriate traffic control system to be used at a highway-rail grade crossing should be determined by an engineering study involving both the highway agency and the railroad company.

ITS

Option. The engineering study may include the Highway-Rail Intersection (HRI) components of the National Intelligent Transportation Systems (ITS) architecture, which is a USDOT accepted method for linking the highway, vehicles and traffic management systems with rail operations and wayside equipment.

Support. More detail on Highway-Rail Intersection components is available from USDOT’s Federal Railroad Administration, 1120 Vermont Ave., NW, Washington, DC 20590, or www.fra.dot.gov.

Standard. Traffic control devices, systems, and practices shall be consistent with the design and application of the Standards contained herein.

Before any new highway-rail grade crossing traffic control system is installed or before modifications are made to an existing system, approval shall be obtained from the highway agency with the jurisdictional and/or statutory authority, and from the railroad company.

Guidance. To stimulate effective responses from vehicle operators and pedestrians, these devices, systems and practices should use the five basic considerations employed generally for traffic control devices and described fully in 903.19.3: design, placement, operation, maintenance and uniformity.

Support. Many other details of highway-rail grade crossing traffic control systems that are not set forth in 903.17 are contained in the publications listed in 903.19.11.

903.17.3 Uniform Provisions (MUTCD Section 8A.03)

Standard. All signs used in highway-rail grade crossing traffic control systems shall be retroreflectorized or illuminated as described in 903.1.15 to show the same shape and similar color to an approaching traveler during both day and night.

No sign or signal shall be located in the center of an undivided highway, except in a raised island.

Guidance. Such signs or signals should be installed with a clearance of at least 2 ft. from the outer edge of the raised island to the nearest edge of the sign or signal, except as allowed in 903.2.1 and 903.3.2.

Where the distance between tracks, measured along the highway between the inside rails, exceeds 100 ft., additional signs or other appropriate traffic control devices should be used.

903.17.4 Highway-Rail Grade Crossing Elimination (MUTCD Section 8A.04)

Guidance. Because highway-rail grade crossings are a potential source of crashes and congestion, agencies should conduct engineering studies to determine the cost and benefits of eliminating these crossings.

Standard. When a highway-rail grade crossing is eliminated, the traffic control devices for the crossing shall be removed.

If the existing traffic control devices at a multiple-track highway-rail grade crossing become improperly placed or inaccurate because of the removal of some of the tracks, the existing devices shall be relocated and/or modified.

Guidance. Any highway-rail grade crossing that cannot be justified should be eliminated.

Where a roadway is removed from a highway-rail grade crossing, the roadway approaches in the railroad right-of-way should also be removed and appropriate signs should be placed at the roadway end in accordance with 620.3 Object Markers.

Where a railroad is eliminated at a highway-rail grade crossing, the tracks should be removed or paved over.

903.17.5 Temporary Traffic Control Zones (MUTCD Section 8A.05)

Support. Temporary traffic control planning provides for continuity of operations (such as movement of traffic, pedestrians and bicycles, transit operations and access to property/utilities) when the normal function of a roadway at a highway-rail grade crossing is suspended because of temporary traffic control operations.

Standard. Traffic controls for temporary traffic control zones that include highway-rail grade crossings shall be as outlined in 616.23 Traffic Control for Field Operations.

When a highway-rail grade crossing exists either within or in the vicinity of a temporary traffic control zone, lane restrictions, flagging or other operations shall not be performed in a manner that would cause vehicles to stop on the railroad tracks, unless a law enforcement officer or flagger is provided at the highway-rail grade crossing to minimize the possibility of vehicles stopping on the tracks, even if automatic warning devices are in place.

Guidance. Public and private agencies, including emergency services, businesses and railroad companies, should meet to plan appropriate traffic detours and the necessary signing, marking and flagging requirements for operations during temporary traffic control zone activities. Consideration should be given to the length of time that the highway-rail grade crossing should be closed, the type of rail and highway traffic affected, the time of day and the materials and techniques of repair.

Temporary traffic control operations should minimize the inconvenience, delay and crash potential to affected traffic. Prior notice should be given to affected public or private agencies, emergency services, businesses, railroad companies and travelers before the free movement of vehicles or trains is infringed upon or blocked.

Temporary traffic control zone activities are not to be permitted to extensively prolong the closing of the highway-rail grade crossing.

The width, grade, alignment and riding quality of the highway surface at a highway-rail grade crossing are, at a minimum, to be restored to correspond with the quality of the approaches to the highway-rail grade crossing.

903.17.6 Signs and Markings (MUTCD Section 8B)

Passive Warning System

Support. Passive traffic control systems, consisting of signs and pavement markings, identify and direct attention to the location of a highway-rail grade crossing and advise motorists, bicyclists, and pedestrians to take appropriate action.

903.17.6.1 Sizes of Grade Crossing Signs. (MUTCD Section 8B.02)

Standard. The sizes of grade crossing signs shall be as shown in Table 903.17.6.3.

Option. Signs larger than those shown in Table 903.17.6.3 may be used (Refer to 903.1.19, Dimensions).

903.17.6.2 Highway-Rail Grade Crossing (Crossbuck) Sign (R15-1) and Number of Tracks Sign (R15-2). (MUTCD Section 8B.03)

Support. The Highway-Rail Grade Crossing (R15-1) sign, commonly identified as the Crossbuck sign, is provided by the appropriate railroad company. Railroads are responsible for the installation and maintenance of these signs.

Standard. The Highway-Rail Grade Crossing (R15-1) sign, commonly identified as the Crossbuck sign, shall be designed and installed in accordance with the MUTCD.

903.17.6.3 Highway-Rail Grade Crossing Advance Warning Signs (W10 Series) (MUTCD Section 8B.04)

903.17.6.3 Highway Rail Grade Crossing W10.jpg

Standard. A Highway-Rail Grade Crossing Advance Warning (W10-1) sign shall be used on each highway in advance of every highway-rail grade crossing.

Placement of the Highway-Rail Grade Crossing Advance Warning sign shall be in accordance with Table 903.6.6, Guidelines for Advance Placement of Warning Sign.

Option. On divided highways and one-way streets, an additional W10-1 sign may be installed on the left side of the roadway.

The PLUS SIDEROAD CROSSING (W10-2), TEE SIDEROAD CROSSING (W10-3), and LEFT (RIGHT) (W10-4L(R)) signs may be installed on highways that are parallel to the railroads. The purpose of these signs is to warn a motorist making a turn from the state system onto another roadway system that a railroad crossing is ahead. On divided highways it is desirable to erect an additional warning sign on the left side of the approaching roadway.

Table 903.17.6.3 Railroad Sign Sizes
Sign Sign Number Section Conventional Expressway (At Grade) Freeway (Grade Separated) Other
RAILROAD CROSSING W10-1 903.17.6.3 42 in. dia. 42 in. dia. - -
PLUS SIDEROAD CROSSING W10-2 903.17.6.3 36 x 36 36 x 36 - -
TEE SIDEROAD CROSSING W10-3 903.17.6.3 36 x 36 36 x 36 - -
RIGHT (LEFT) SIDEROAD CROSSING W10-4R(L) 903.17.6.3 36 x 36 36 x 36 - -
EXEMPT (black on white) R15-3 903.17.6.4 24 x 12 24 x 12 - 24 x 12 (ramp)
EXEMPT (black on yellow) W10A-24 903.17.6.4 24 x 12 24 x 12 - 24 x 12 (ramp)
DO NOT STOP ON TRACKS R8-8 903.17.6.6 24 x 30 24 x 30 - 24 x 30 (ramp)
STOP HERE ON RED R10-6 903.17.6.10 24 x 36 - - -

Standard. If the distance between the railroad tracks and a parallel highway, from the edge of the tracks to the edge of the parallel roadway, is less than 100 ft., W10-2, W10-3, or W10-4 signs shall be installed on each approach of the parallel highway to warn travelers making a turn that they will encounter a highway-rail grade crossing soon after making a turn and a W10-1 sign for the approach to the tracks shall not be required to be between the tracks and the parallel highway.

If the W10-2, W10-3, or W10-4 signs are used, sign placement in accordance with the guidelines for Intersection Warning signs in Table 903.6.6 using the speed of through traffic shall be measured from the highway intersection.

Guidance. If the distance between the railroad tracks and the parallel highway, from the edge of the tracks to the edge of the parallel roadway, is 100 ft. or more, a W10-1 sign should be installed in advance of the highway-rail grade crossing and the W10-2, W10-3, or W10-4 signs should not be used on the parallel highway.

903.17.6.4 EXEMPT Highway-Rail Grade Crossing Signs (R15-3, W10a-24) (MUTCD Section 8B.05)

Option. When authorized by Multimodal Operations, a supplemental EXEMPT (R15-3) sign with a white background bearing the word EXEMPT may be used below the Crossbuck sign or Number of Tracks sign, if present, at the highway-rail grade crossing, and a supplemental EXEMPT (W10a-24) sign with a yellow background bearing the word EXEMPT may be used below the Highway-Rail Advance Warning (W10-1) sign.

Support. These supplemental signs inform drivers of vehicles carrying passengers for hire, school buses carrying students or vehicles carrying hazardous materials that a stop is not required at certain designated highway-rail grade crossings, except when a train, locomotive or other railroad equipment is approaching or occupying the highway-rail grade crossing, or the driver's view is blocked.

903.17.6.5 Turn Restrictions During Preemption (MUTCD Section 8B.06)

Guidance. At a signalized intersection that is located within 200 ft. of a highway-rail grade crossing, measured from the edge of the track to the edge of the roadway, where the intersection traffic control signals are preempted by the approach of a train, all existing turning movements toward the highway-rail grade crossing should be prohibited during the signal preemption sequences.

Option. A blank-out or changeable message sign and/or appropriate highway traffic signal indication or other similar type sign may be used to prohibit turning movements toward the highway-rail grade crossing during preemption.

Standard. Turn prohibition signs that are associated with preemption shall be visible only when the highway-rail grade crossing restriction is in effect.

903.17.6.6 DO NOT STOP ON TRACKS Sign (R8-8) (MUTCD Section 8B.07)

Guidance. Whenever engineering judgment determines that the potential for vehicles stopping on the tracks is high, a DO NOT STOP ON TRACKS (R8-8) sign should be used.

The sign, if used, should be located on the right side of the highway on either the near or far side of the highway-rail grade crossing, depending upon which side provides better visibility to approaching drivers.

Option. DO NOT STOP ON TRACKS signs may be placed on both sides of the track.

On divided highways and one-way streets, a second DO NOT STOP ON TRACKS sign may be placed on the near or far left side of the highway-rail grade crossing to further improve visibility of the sign.

903.17.6.7 STOP (R1-1) or YIELD (R1-2) Signs at Highway-Rail Grade Crossings. (MUTCD Section 8B.08)

Option. When authorized by MoDOT (Multimodal Operations), STOP (R1-1) or YIELD (R1-2) signs may be used at highway-rail grade crossings that are without automatic traffic control devices.

For other highway-rail grade crossings with passive warning devices, STOP or YIELD signs may be used based on an engineering study.

Guidance. The engineering study should take into consideration such factors as highway and train traffic characteristics (including volume and speed), collision history, the need for active control devices, and sight distance to the approaching train.

Option. If a STOP or YIELD sign is installed at a highway-rail grade crossing, it may be installed on the Crossbuck post or on a separate post at a point where the vehicle should stop, or as near to that point as practical. In some cases a STOP sign may be used on one approach and a YIELD sign may be used on the other approach.

Standard. For all highway-rail grade crossings where STOP or YIELD signs are installed, the placement shall conform to the requirements of 903.5.4.2 and 903.5.5.2. Stop Ahead (W3-1) or Yield Ahead (W3-2) Advance Warning signs shall also be installed if the criteria for their installation given in 903.6.31 is met.

Support. MoDOT’s Multimodal Operations Division has developed a Stop-Yield Sign Fact Sheet to help determine where Stop or Yield signs should be used, located at 903.5.4 and 903.5.5.

903.17.6.8 TRACKS OUT OF SERVICE Sign (R8-9) (MUTCD Section 8B.029)

Support. Not used in Missouri.

903.17.6.9 STOP HERE ON RED Sign (R8-10) (MUTCD Section 8B.10)

Support. Not used in Missouri.

903.17.6.10 STOP HERE ON RED Sign (R10-6) (MUTCD Section 8B.11)

Support. The STOP HERE ON RED (R10-6) sign defines and facilitates observance of stop lines at traffic control signals.

Option. A STOP HERE ON RED sign may be used at locations where vehicles frequently violate the stop line or where it is not obvious to travelers where to stop.

Guidance. If possible, stop lines should be placed at a point where the vehicle driver has adequate sight distance along the track.

903.17.6.11 TRAINS MAY EXCEED 80 MPH Sign (W10-8) (MUTCD Section 8B.13)

Support. Not used in Missouri.

903.17.6.12 NO TRAIN HORN Sign (W10-9) (MUTCD Section 8B.14)

Support. Not used in Missouri.

903.17.6.13 NO SIGNAL HORN Sign (W10-13) (MUTCD Section 8B.15)

Support. Not used in Missouri.

903.17.6.14 LOOK Sign (R15-8) (MUTCD Section 8B.16)

Support. Not used in Missouri.

903.17.6.15 Low ground clearance Highway-Rail Grade Crossing Sign (W10-5) (MUTCD Section 8B.17)

Support. Not used in Missouri.

903.17.6.16 Storage Space Signs Signs (W10-11, W10-11a, W10-11b) (MUTCD Section 8B.18)

Support. Not used in Missouri.

903.17.6.17 Skewed Crossing Sign (W10-12) (MUTCD Section 8B.19)

Support. Not used in Missouri.

903.17.6.18 Pavement Markings. (MUTCD Section 8B.20)

Refer to 620, Pavement Marking for additional information.

Standard. All highway-rail grade crossing pavement markings shall be retroreflectorized white. All other markings shall be in accordance with Part 3 of the federal MUTCD.

Pavement markings in advance of a highway-rail grade crossing shall consist of 2 (not including the stop bar) 2-ft. wide transverse lines and a R X R symbol in the lane approaching the crossing, a no-passing marking (two-lane highways where centerline markings are used) and certain transverse lines as shown in Figures 903.17.6.19.1, 903.17.6.19.2 and 903.17.6.19.3.

The R X R symbol shall be elongated to allow for increased low angle visibility from a traveling vehicle.

The length of the no passing shall be determined by the posted or 85th percentile speed.

Identical markings shall be placed in each approach lane on all paved approaches to highway-rail grade crossings where signals or automatic gates are located and at all other highway-rail grade crossings where the posted or statutory highway speed is 40 mph or greater.

Pavement markings are suggested, but not required, at highway-rail grade crossings where the posted or statutory highway speed is less than 40 mph, or in urban areas, if an engineering study indicates that other installed devices provide suitable warning and control.

The district office shall review each new crossing to determine the exact location of the required permanent markings.

The pavement markings and all other traffic control devices on the approaches to at grade railroad crossings shall be removed if:

A. The district has been notified by the Multimodal Operations Division that the rail line has been officially abandoned; or

B. The track has been removed or covered with asphalt with the consent of the railroad.

Refer to Highway-Rail Grade Crossing Elimination for additional information.

Guidance. When pavement markings are used, a portion of the X symbol should be directly opposite the Advance Warning sign.

Option. When justified by engineering judgment, supplemental pavement marking symbol(s) may be placed between the Advance Warning sign and the highway-rail grade crossing.

Modifications may be made to the placement and design of these marking to provide visibility and pre-warning in unusual circumstances. These changes may be required when the standard placement locates these markings in front of entrances or between the railroad and street intersections.

At locations where a railroad and highway run parallel and where there is a very short distance between an intersection and the railroad crossing, the standard R X R pavement markings may be omitted.

Guidance. At locations where a railroad and highway are parallel, there is a very short distance between an intersection and the railroad crossing and the road maintained by MoDOT crosses the railroad and the parallel roadway, a second R X R symbol should be placed on the far side of the parallel roadway (See Figure 903.17.6.19.2).

At locations where there are parallel railroad tracks, requiring two or more railroad crossings in close proximity, the no passing zones and railroad pavement markings should be as follows:

A. No passing zone markings should be provided between all tracks if the tracks are more than 20 ft. apart;

B. Additional railroad marking symbols should be provided at the mid-point between tracks if the tracks are spaced 300 ft. to 800 ft. apart; and

C. Standard R X R marking applications should be provided if the distance between the tracks is greater than 800 ft.

903.17.6.19 Stop Lines. (MUTCD Section 8B.21)

Refer to 620, Pavement Marking for additional information.

Guidance. The stop line should be a transverse line at a right angle to the travelway at a point where a vehicle should stop or as near to that point as possible. The stop line should be placed approximately 8 ft. from the gate (if present), but no closer than 15 ft. from the nearest rail.

Figure 903.17.6.19.1. Standard Railroad Crossing Pavement Markings (Tracks Perpendicular to Roadway)
Figure 903.17.6.19.2. Railroad Crossing Pavement Markings(Tracks Parallel to Roadway)
Figure 903.17.6.19.3. Stop Bar Locations for Railroad Crossings (Crossings Equipped with Flashing Lights or Gates)

903.17.7 Illumination at Highway-Rail Crossings (MUTCD Section 8C.01)

Option. Illumination may be installed at or adjacent to a highway-rail grade crossing.

Guidance. If an engineering study is conducted and if the engineering study determines that better nighttime visibility of the train and the highway-rail grade crossing is needed (for example, where a substantial amount of railroad operation is conducted at night, where train speeds are low and highway-rail grade crossings are blocked for long periods, or crash history indicates that drivers experience difficulty in seeing trains or traffic control devices during hours of darkness), then illumination should be installed at and adjacent to the highway-rail grade crossing.

Support. Types and location of luminaires for highway-rail grade crossing illumination are contained in the American National Standards Institute’s (ANSI) Practice for Roadway Lighting RP-8 available from the Illuminating Engineering Society.

903.17.8 Illumination at Highway-Rail Grade Crossings (MUTCD Section 8C)

Illumination may be installed at or adjacent to a highway-rail grade crossing.

If an engineering study is conducted and if the engineering study determines that better nighttime visibility of the train and the highway-rail grade crossing is needed (for example, where a substantial amount of railroad operation is conducted at night, where train speeds are low and highway-rail grade crossings are blocked for long periods, or crash history indicates that drivers experience difficulty in seeing trains or traffic control devices during hours of darkness), then illumination should be installed at and adjacent to the highway-rail grade crossing.

Types and location of luminaires for highway-rail grade crossing illumination are contained in the American National Standards Institute’s (ANSI) “Practice for Roadway Lighting RP-8” available from the Illuminating Engineering Society (see 903.19.11).

903.17.9 Flashing Light Signals, Gates and Traffic Control Signals (MUTCD Section 8D)

903.17.9.jpg

Support. Active traffic control systems inform motorists, bicyclists and pedestrians of the approach or presence of trains, locomotives or other railroad equipment at highway-rail grade crossings.

The design, installation and maintenance of these devices are normally the responsibility of the corresponding railroad company with the approval of MoDOT (a function of the Multimodal Operations Division).

Standard. Active traffic control systems at railroad crossing shall be designed and installed in accordance with the MUTCD.

903.17.9.1 Flashing-Light Signals, Post-Mounted (MUTCD Section 8D.02)

Support. See the MUTCD.

903.17.9.2 Flashing-Light Signals, Overhead Structures (MUTCD Section 8D.03)

Support. See the MUTCD.

903.17.9.3 Automatic Gates (MUTCD Section 8D.04)

Support. See the MUTCD.

903.17.9.4 Four-Quadrant Gate Systems (MUTCD Section 8D.05)

Support. See the MUTCD.

903.17.9.5 Train Detection (MUTCD Section 8D.06)

Support. See the MUTCD.

903.17.9.6 Traffic Control Signals at or Near Highway-Rail Grade Crossings (MUTCD Section 8D.07)

Option. Traffic control signals may be used instead of flashing-light signals to control travelers at industrial highway-rail grade crossings and other places where train movements are very slow, such as in switching operations.

Standard. The appropriate provisions of Part 4 of the MUTCD relating to traffic control signal design, installation and operation shall be applicable where traffic control signals are used to control travelers instead of flashing-light signals at highway-rail grade crossings.

Traffic control signals shall not be used instead of flashing-light signals to control travelers at a mainline highway-rail grade crossing.

Guidance. MoDOT and the railroad company should jointly determine the preemption operation at highway-rail grade crossings adjacent to signalized highway intersections.

If a highway-rail grade crossing is equipped with a flashing-light signal system and is located within 200 ft. of an intersection or midblock location controlled by a traffic control signal, the traffic control signal should be provided with preemption in accordance with Section 4D.13 of the federal MUTCD.

Coordination with the flashing-light signal system, queue detection, or other alternatives should be considered for traffic control signals located farther than 200 ft. from the highway-rail grade crossing. Factors to be considered should include traffic volumes, vehicle mix, vehicle and train approach speeds, frequency of trains and queue lengths.

Standard. If preemption is provided, the normal sequence of traffic control signal indications shall be preempted upon the approach of trains to avoid entrapment of vehicles on the highway-rail grade crossing by conflicting aspects of the traffic control signals and the highway-rail grade crossing flashing-light signals.

This preemption feature shall have an electrical circuit of the closed-circuit principle, or a supervised communication circuit between the control circuits of the highway-rail grade crossing warning system and the traffic control signal controller. The traffic control signal controller preemptor shall be activated via the supervised communication circuit or the electrical circuit that is normally energized by the control circuits of the highway-rail grade crossing warning system. The approach of a train to a highway-rail grade crossing shall de-energize the electrical circuit or activate the supervised communication circuit, which in turn shall activate the traffic control signal controller preemptor. This shall establish and maintain the preemption condition during the time the highway-rail grade crossing warning system is activated, except that when crossing gates exist, the preemption condition shall be maintained until the crossing gates are energized to start their upward movement. When multiple or successive preemptions occur, train activation shall receive first priority.

Guidance. If a highway-rail grade crossing is located within 50 ft. (or within 75 ft. for a highway that is regularly used by multi-unit vehicles) of an intersection controlled by a traffic control signal, the use of pre-signals to control traffic approaching the grade crossing should be considered.

Standard. If used, the pre-signals shall display a red signal indication during the track clearance portion of a signal preemption sequence to prohibit additional vehicles from crossing the railroad track.

Guidance. Consideration should be given to using visibility-limited signal faces (see Section 4A.02 of theMUTCD) at the intersection for the downstream signal faces that control the approach that is equipped with pre-signals.

Option. The pre-signal phase sequencing may be timed with an offset from the signalized intersection such that the railroad track area and the area between the railroad track and the downstream signalized intersection is generally kept clear of stopped vehicles.

Standard. If a pre-signal is installed at an interconnected highway-rail grade crossing near a signalized intersection, a STOP HERE ON RED (R10-6) sign shall be installed near the pre-signal or at the stop line if used. If there is a nearby signalized intersection with insufficient clear storage distance for a design vehicle, or the highway-rail grade crossing does not have gates, a NO TURN ON RED (R10-11) sign shall be installed for the approach that crosses the railroad track.

Option. At locations where a highway-rail grade crossing is located more than 50 ft. (or more than 75 ft. for a highway regularly used by multi-unit vehicles) from an intersection controlled by a traffic control signal, a pre-signal may be used if an engineering study determines a need.

If highway traffic signals must be located within close proximity to the flashing-light signal system, the highway traffic signals may be mounted on the same overhead structure as the flashing-light signals.

Support. Section 4D.13 of the federal MUTCD describes additional considerations regarding preemption of traffic control signals at or near highway-rail grade crossings.