Transit and On-Street Rail

The MUTCD Section 8A.01 refers to LRT as “a mode of metropolitan transportation that employs LRT vehicles (commonly known as light rail vehicles, streetcars, or trolleys) that operate on rails in streets in mixed traffic, and LRT traffic that operates in semi ‑exclusive rights ‑ of-way, or in exclusive rights-of-way. Grade crossings with LRT can occur at intersections or at midblock locations, including public and private driveways.” T raffic control for LRT is determined in part by the type of alignment:

•Exclusive—This type of alignment does not have grade crossings. The alignment is grade- separated or protected by a fence or traffic barrier. Motor vehicles, pedestrians, and bicycles are prohibited within the traveled way. Subways and aerial structures are included within this group. Because the alignment does not have grade crossings, there are no provisions for traffic control devices.

•Semi-exclusive—An alignment where the LRT operates within a separate traveled way or along a street or railroad ROW where motor vehicles, pedestrians, and bicycles have limited access and cross at designated locations only. In a semi-exclusive alignment, LRT vehicles usually have ROW over other roadway users at grade crossings.

•Mixed ‑use—An alignment where the LRT operates in mixed traffic with all types of road users. This includes streets, transit malls, and pedestrian malls where the traveled way is shared. In a 97mixed-use alignment, the LRT vehicles or buses do not have ROW over other roadway users at grade crossings and intersections and LRT vehicles are usually controlled with the same devices used by general traffic. It is important to understand that provisions in Part 8 of the MUTCD are intended to be applicable to both LRT and conventional railroads; therefore, when the phrase “grade crossing” is used by itself without the prefix “highway ‑rail” or “highway ‑LRT” it refers to both highway ‑ rail and highway ‑LRT crossings. Conversely, LRT ‑ specific provisions are indicated as applicable to “Highway-LRT Grade Crossings.” (In accordance with FRA requirements,(32) where LRT operates in the same corridor, e.g., “shared corridor” or on the same track as conventional rail, FRA requirements are applicable to both the conventional rail crossings as well as the LRT crossings in that corridor.) The MUTCD does not define the term “streetcar.” Although streetcar vehicles and trains resemble LRT, where streetcars operate in “mixed flow” in the same travel lane as other highway vehicles, traffic control treatments and provisions applicable to highway traffic in general are applicable to the streetcar operation. Where a streetcar operates in a semi ‑ exclusive alignment, provisions and traffic control treatments applicable to LR T operating in a semi-exclusive alignment should be considered. The LRT Traffic Control Systems is the overarching term used to describe the combination of devices selected or installed at a specific highway ‑LRT crossing. According to MUTCD Section 8A.03, there is not a single standard system universally applicable due to the many significant variables to be considered. The selection of traffic control devices and the assignment of priority to LRT at a highway-LRT crossing is jointly determined by the highway agency with jurisdiction, the regulatory agency with statutory authority, if applicable, and the LRT authority. The normal rules of the road and traffic control priority identified in the “Uniform V ehicle Code” govern the order assigned to the movement of vehicles at an intersection unless the local agency determines that it is appropriate to assign a higher priority to LRT.(9) The LRT ‑ specific MUTCD provisions are provided in Sections 8A.01 (Introduction), 8A.03 (Use of Standard Devices, Systems, and Practices), 8B.05 (STOP and YIELD signs), 8C.03 (Flashing- Light Signals), 8C.05 (Automatic Gates) and 8C.10 (Traffic Control Signals at or Near Highway ‑ LRT Grade Crossings), 8C.11 (Use of Traffic Control Signals for Control of LRT Vehicles), and 8C.13 (Pedestrian and Bicycle Signals). Key requirements are as follows:

•Section 8A.03 requires that Highway-LRT grade crossings in semi-exclusive alignments shall be equipped with a combination of automatic gates and flashing ‑light signals, or flashing ‑light signals only, or traffic control signals, unless an engineering study indicates that the use of Crossbuck Assemblies, STOP signs, or YIELD signs alone would be adequate.

•Section 8B.03 and 8B.04 contain provisions regarding the use and placement of Crossbuck signs and Crossbuck Assemblies. Section 8B.05 describes the appropriate conditions for the use of STOP of YIELD signs alone at a highway-LRT grade crossing. Sections 8C.10 and 8C.11 contain provisions regarding the use of traffic control signals at highway ‑LRT grade crossings.

•Section 8C.05 has various provisions depending upon the alignment, LRT speeds, and traffic conditions which can be summarized as follows: 98 ̶Where LRT speeds exceed 35 mph, highway-LRT crossings “should” be equipped with automatic gates and flashing ‑light signals. ̶At LRT crossings “within highway-highway intersections” where LRT speeds do not exceed 35 mph, traffic control signals may be used instead of automatic gates. ̶Where LRT speeds exceed 25 mph and a highway-LRT crossing is at a location “other than an intersection,” automatic gates and flashing ‑light signals “may” be installed (but are not required). ̶At LRT crossings “other than an intersection” where the roadway is a low-volume street where prevailing speeds do not exceed 25 mph and where LRT speeds do not exceed 25 mph, traffic control signals or flashing ‑light signals without automatic gates “may” be used. For additional information, reference the MUTCD (2009) Section 8A.03, Use of Standard Devices, Systems, and Practices at Highway-LRT Crossings.

Control of Motor Vehicle Turning Treatments

Motor vehicles making illegal turns in front of approaching light-rail vehicles (LRV) are one of the most common types of collision for most LRT systems.(33) Moreover, when such a collision occurs, the door of the motor vehicle is the only protection between the driver/passenger and the LRV , which makes turning collisions one of the most severe types of collisions between motor vehicles and LRVs. Traffic control devices that regulate turns are critical to LRT and general traffic safety. Current practice is to provide dedicated turn lanes for traffic turning toward the LRT crossing where practicable with traffic control signal indications for such movements. Where turning traffic crosses a non ‑gated, semi ‑exclusive LRT alignment and is controlled by left ‑ or right-turn arrow signal indications, Transit Cooperative Research Program (TCRP) Report 17 recommends that the LRT agency install an LRV ‑ activated, flashing, internally illuminated warning sign displaying the front view LRV symbol (W10-7) when the LRV approaches.(34) When such a sign is used, the turn arrow signal indication serves as the primary regulatory control device and the flashing, internally illuminated warning sign supplements it, warning motorists of the increased risk associated with violating the turn arrow signal indication. The MUTCD allows use of this sign at LRT crossings controlled by STOP signs or automatic gates. Where turning traffic crosses a non ‑gated, semi ‑exclusive LRT alignment and is controlled by a STOP sign or signal without a turn arrow (such as a permissive left or right turn), TCRP Report 17 recommends that an LRV-activated, internally illuminated “NO LEFT/RIGHT TURN” (R3- 2/R3-1) symbol sign be provided to restrict left or right turns when an LRV is approaching (see Figure 46). (34) Because these signs would serve as the primary control devices regulating turning movements, TCRP Report 17 recommends that two signs be provided for each parallel approach. The LRV-activated, internally illuminated sign displaying the legend NO LEFT/RIGHT TURN may be used as an alternate to the active, internally illuminated symbol sign. Figure 46. No Turns Internally Illuminated Signs 100Table 6 summarizes the recommended practices for the active, internally illuminated “NO LEFT/RIGHT TURN” symbol sign (regulatory) and the flashing, internally illuminated “TRAIN APPROACHING” sign (warning) for median or side-running LRT alignments where parallel traffic may proceed during LRV movements. Table 6. Use of Active Internally Illuminated Signs for Parallel Traffic

Turning Across LRT Tracks

Alignment Type Intersection Traffic

Control Device“NO LEFT/RIGHT

TUrn Across

TRACKS” SignTrain Icon Sign for

Left/Right Turnsa

Semi-exclusive

gatedStopcRecommended May

Traffic signal without

arrowdRecommendedbMay

Traffic signal with arroweNot recommended May

Semi-exclusive

non-gatedStopcRecommended May

Traffic signal without

arrowdRecommendedbMay

Traffic signal with arroweNot recommended Recommended

a Left-turn signs are for median and side-aligned LR T alignments; right-turn signs are for side-aligned LRT alignments only. b Alternatively , an all-red phase for motor vehicles and pedestrians may be used in combination with “No Turn On Red” (R10-11a) signs. c “Stop” refers to a STOP sign-controlled intersection. d “Without arrow” refers to a signalized intersection at whic h the turning traffic has no red arrow displayed when an LRV is approaching but has either a steady green ball, a red ball, or a flashing red ball displayed. e “With arrow” refers to a signalized intersection at which the turning traf fic has a red arrow displayed when an LRV is approaching. When a turn arrow traffic signal indication is used, TCRP Report 17 recommends that an exclusive turn lane be provided. Source: Adapted from Korve, Hans W., Jose I. Farran, Douglas M. Mansel, et al. Integration of Light Rail Transit into City Streets, Washington, DC, TRCP Report 17, TRB, 1996. For semi ‑exclusive alignments, all traffic conflicting with LRV movements at intersections and crossings should be positively controlled through use of turn pockets, traffic signals, and active warning signs. 101LRT Bar Signals The MUTCD Section 8C.11 provides the following guidance for use of LRT signals (refer to Figure 47):

•LRT movements in semi-exclusive alignments at non-gated crossings that are equipped with traffic control signals should be controlled with LRT Bar Signals.

•LRT signals that are used to control LRT movements only should display the signal indications illustrated in MUTCD Figure 8C-3.

•Standard traffic control signal indications may be used instead of LRT signals to control the movement of LRT vehicles (see Section 8C.10).

•Note that Section 4D.27 contains information about the use of LRT signals for the control of exclusive bus movements at “queue jumper lanes” and for the control of exclusive bus rapid transit movements on semi-exclusive or mixed-use alignments. Figure 47. LRT Signals Source: Manual on Uniform Traffic Control Devices, 2009 Edition, Figure 8C-3, Washington, DC, FHWA, 2009. 102Pedestrian and Bicycle Signals at LRT Crossings The MUTCD Section 8C.13 requires use of standard traffic control signal pedestrian signal heads compliant with Section 4E.04 where such heads are used at LRT crossings. Consistent with current practice, the MUTCD indicates flashing ‑light signals with a Crossbuck sign and audible device should be used where there is inadequate clearing sight distance ( refer to sight distance information in Chapter 2 ), or where LRT speeds exceed 35 mph. The MUTCD also allows use of the LOOK sign (R15-8) and/or pedestrian gates subject to an engineering study which indicates a flashing ‑light signal with Crossbuck would not be adequate. In addition, the MUTCD allows use of pedestrian “swing gates” as an option. Common practice includes use of swing gates in conjunction with pedestrian automatic gates where the swing gates can be used to provide a means of egress for users who are within the crossing zone when crossing gates are activated. (Refer to MUTCD Chapter 8D for additional swing gate provisions.)