Bus Rapid Transit, Volume 2: Implementation Guidelines (2003)

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4-1 CHAPTER 4 TRAFFIC ENGINEERING FOR BRT Traffic-transit operations integration is an essential com- ponent of the planning design and operation of BRT run- ning ways. Close working relationships between traffic engi- neers and transit planners is essential in developing bus lane and busway designs, locating bus stops, and applying traffic controls. A good program of traffic controls and signage should help ensure safe vehicle and pedestrian crossings of bus lanes and busways and minimize delays to BRT vehicles and general traffic. Good traffic controls and signage will maintain essen- tial access to curbside activities and provide a reasonable allo- cation of street space among competing uses—BRT, other buses, and curbside access for general traffic and pedestrians. The program of traffic controls and signage should be per- ceived as reasonable by bus passengers, motorists, and abut- ting land users. An effective enforcement program is essen- tial. This chapter provides traffic engineering guidelines for the various types of running ways. Further details can be found in the Institute of Transportation Engineers Traffic Engineering Handbook (Pline, 1999). 4-1. OVERVIEW The specific traffic engineering techniques vary with the type and location of BRT running ways. These techniques can be grouped in four basic categories: (1) traffic controls, (2) special signs and signal displays, (3) traffic signal con- trols and priorities, and (4) enforcement. Applications of these techniques are shown in Table 4-1. The techniques are mainly applicable to street-running BRT, but they also apply wherever busways or freeway bus lanes interface with roads and streets, such as at intersections. The techniques include (1) controls for curb parking, left turns, right turns, and one-way streets; (2) special signage and traffic signal displays; and (3) traffic signal controls, including BRT preference and priority. Additional tech- niques include curb adjustments, changes in roadway geom- etry, and pavement markings. Some general guidelines are as follows: • Stop signs or traffic signals should be placed on streets that intersect BRT routes. • Curb parking (all day or during rush hours) should gen- erally be restricted along BRT running ways. • Left and right turns should be restricted when they can- not be accommodated without delaying BRT. • Special signage should define BRT running ways and inform motorists of at-grade busway crossings. • Special BRT traffic signal indicators should be provided to minimize motorist confusion, especially along median arterial busways and at queue jumps. • Red times (and hence delays) for buses should be kept to a minimum. This can be achieved by (1) maximizing the available green time, (2) using as short a traffic sig- nal cycle length as possible, and/or (3) appropriately advancing and extending green time as BRT vehicles approach intersections. • ITS technologies can enhance and better integrate traf- fic engineering and control measures. This is described more fully in Chapter 7. 4-2. TRAFFIC CONTROLS Traffic controls relating to curb use, turning movements, and street directions can be applied at individual locations, on selected segments, or on an entire BRT route. 4-2.1. Curb Parking and Loading Controls Curb parking problems are especially acute in older parts of urban areas where activities are clustered and off-street parking space is limited. Curb parking problems are a major concern within central areas, outlying business districts, and along streets lined with shops and offices. These are often corridors with good BRT market potential, which are served by BRT running ways. Curb parking reduces the space available for buses and auto- mobiles, conflicts with movement in adjacent lanes, reduces bus and automobile speeds, and increases accidents. Parking prohibitions where there are major bus facilities have reduced accidents by about 15 to 20% and have increased travel speeds for all vehicles. Accordingly, there should be no parking along BRT routes in congested areas and along heavily traveled arteries, at least during rush hours. However, parking can be retained along streets with “interior,” or median, bus lanes or along lightly traveled streets where bus bulbs are provided for passenger convenience.

4-2 Curb parking can be prohibited at all times or just during rush hours. When BRT uses curb bus lanes throughout the day, it is possible to use distinctively colored pavements to identify the lanes. As a general rule, curb parking should be prohibited during busy traffic periods when traffic volumes exceed 500 to 600 vehicles per lane per hour; the street oper- ates at “Level of Service” E or F, automobile speeds fall below 20 to 25 miles per hour, and the lane is needed for bus or BRT use. Off-street loading areas are desirable along BRT routes. 4-2.2. Turn Controls Left and right turns can seriously impede BRT and gen- eral traffic flow at many locations. The “right-turn prob- lem” is usually critical in areas of heavy pedestrian activity with both narrow corner radii and major pedestrian cross- ings (e.g., often where stations are located.) These condi- tions usually are found in the city center and older high- density neighborhoods. Left turns, however, create problems throughout the street system. They not only con- flict with opposing through traffic, but they also may block the vehicles behind them and complicate traffic signal phasing. Because of problems with left and right turns, left- and right-turn restrictions are used in many urban areas to pre- serve capacity and to reduce congestion. The controls may be in effect all day, from 7 a.m. to 7 p.m., or during rush hours only. From a BRT perspective, these controls are desirable. The general principle is that when turns create problems, they should be prohibited. At places where BRT and other bus routes turn from one street to another, the buses gener- ally should be exempted from any turn restrictions. Many communities provide such exemptions. 4-2.2.1. Right Turns Right-turn restrictions may be appropriate at locations where BRT operates in mixed traffic, curb bus lanes, or “interior” bus lanes and where both right turns and pedes- trian volumes are heavy. Each pedestrian per channel takes a specified time to cross the area in which there is conflict with right turns; in effect, each pedestrian delays each right turn by this time. The time lost can be estimated by weight- ing the time per pedestrian by the number of pedestrians and right turns per signal cycle. The travel times gained by restricting right turns can then be approximated from the following equation: Where ∆t = green time to be gained per cycle, r = right turns/cycle (peak 15 minutes), p = conflicting pedestrians/cycle (peak 15 minutes), ts = time per pedestrian (e.g., 3 to 4 seconds), and L = number of pedestrian channels in crosswalk (e.g., 1 to 4). ∆t r pt L s = TABLE 4-1 Typical BRT applications of traffic engineering techniques Traffic Controls Special Signs and SignalDisplays Traffic Signal Controls and Priorities Type of Running Way Curb Parking Restrictions Right-Turn Restrictions Left-Turn Restrictions One-Way Streets Signs Signals Passive Priority Active Priority Enforce- ment Busways Tunnels ✓ Grade Separated ✓ ✓ a ✓ a ✓ At grade ✓ b ✓ ✓ ✓ ✓ Freeway Lanes Concurrent Flow ✓ Contra Flow ✓ Bus-Only Ramps ✓ Priority at Metered Ramps ✓ ✓ Arterial Streets Median Arterial Busway ✓c ✓ ✓ ✓ c ✓ c ✓ Curb Bus Lanes ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Dual Curb Lanes ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Interior Bus Lanes ✓ ✓ ✓ ✓ ✓ ✓ ✓ Median Bus Lanes ✓ ✓ ✓ ✓ ✓ Contra Flow Lanes ✓ ✓ ✓ Bus-Only Street ✓ ✓ ✓ ✓ ✓ ✓ ✓ Mixed Traffic Flow ✓ ✓ ✓ ✓ ✓ ✓ ✓ Queue Bypass ✓ ✓ ✓ ✓ ✓ ✓ NOTES: a Only at busway access points. b On both busways and cross streets. c Special left-turn phasing where left turns are permitted.

Estimated time lost per signal cycle by conflicting right turns and pedestrian volumes is shown in Table 4-2. For example, if there were 300 pedestrians per hour conflicting with 240 right turns per hour (5 and 4 per cycle), and 3 sec- onds lost per conflict, about 20 seconds per cycle would be lost, assuming 3 pedestrian channels. If the turns were pro- hibited, the curb lane would then gain an additional 20 sec- onds of effective green time. Thus, to ensure a minimum effective green time of 25% of the cycle, it would be neces- sary to prohibit the right turns in this case. 4-2.2.2. Left Turns Left turns at intersections along BRT routes may be per- mitted when protected left-turn lanes are provided. In some cases, special signal phases for the turns may be necessary. However, left turns generally should be prohibited when the turns share lanes with through traffic. Shared lanes cut lane capacity by about 50%, delay through vehicles, and increase accidents. One left turn per signal cycle delays 40% of the through vehicles in the shared lane. When BRT operates in median arterial busways, it is essential to either prohibit left turns from the parallel road- ways or to provide protected signal phases for the turns. Pro- tected signal phasing is also essential when there are multi- ple left-turn lanes. When street patterns permit and there are alternative street routings, prohibition of left turns along BRT routes is desirable. The prohibition will simplify traffic signal phasing, reduce queues, and improve both bus and general traffic flow. On a 1-mile trip that takes 4 minutes (15 miles per hour), about 0.5 minutes are lost because of left- turn delays. With the turns prohibited, the trip takes 3.5 min- utes, a savings of 12.5%. There are other ways to accommodate left turns, including far-side “Michigan U-Turns” and “Jersey Jug Handles.” Both of these strategies convert left turns into right turns. If 4-3 space permits, these strategies for accommodating left turns should be explored. 4-2.3. One-Way Streets One-way streets can facilitate bus, automobile, and truck flow. Traffic moves in one direction, thereby reducing con- flicts and crashes, simplifying traffic signal phasing, and improving traffic signal progression. The benefits of one- way streets in improving safety and traffic flow have been well documented. Travel time reductions of about 25% are common, capacity may be increased by 20 to 40%, and acci- dents can be reduced by 10 to 50%. Thus, one-way streets can improve BRT speed and reliability in both mixed traffic and in bus lanes. With wide spacing between bus stops, buses can keep up with the signal progression, especially where dwell times at stops are low. One-way streets are essential in downtown street grids with narrow and closely spaced blocks. There are, however, several disadvantages to one-way streets from a BRT perspective. These disadvantages include the following: • BRT service is divided into two parallel streets with attendant losses in BRT identity. • The streets may preclude curbside passenger access when activities are located between the two one-way streets. • When activities are concentrated along one street, pas- senger walking distances are increased. • The number of curb faces where buses can pick up or dis- charge passengers could be cut in half. Sometimes, these concerns can be overcome by running buses two ways on one of the streets (e.g., one direction in a contra flow lane). Figure 4-1 shows how a contra flow bus lane can be used to keep buses going two ways on a central area one-way street grid. Buses are able to (1) eliminate three Time Loss per Cycle at 3 seconds per Pedestrian Channels (lanes) Typical Values of R/Nc and P/Nc 1 Lane 2 Lanes 3 Lanes 4 Lanes 4 12 6 4 3 8 24 12 8 6 12 36 18 12 9 16 48 24 16 12 20 60 30 20 15 24 72* 36 24 18 NOTES: For a 60-second cycle, time loss should not exceed 25% of cycle or 15 seconds. Thus, values below the boldface lines are not acceptable, and turns should be prohibited. * = excess cycle length R = right turns per hour Nc = number of cycles per hour P = pedestrians per hour TABLE 4-2 Estimated time lost per cycle by conflicting right turns and pedestrian volumes

turns, (2) reduce bus mileage, and (3) maximize the presence of buses on a single street. 4-3. SPECIAL SIGNAGE AND SIGNAL DISPLAYS Special signage and traffic signal displays are desirable along BRT routes. They should be installed in general accord with the provisions of the Manual of Uniform Traffic Con- trol Devices for Streets and Highways, Millennium Edition (MUTCD) (2001). 4-3.1. Traffic Signs Standard diamond signs, used for bus and HOV lanes, should be used for BRT running ways. As indicated in Chapter 4 of the MUTCD, they can be placed over the lanes or be mounted along the side of the roadway (2001). Their spacing should be based on engineering judgment that con- siders prevailing speeds, block lengths, and distances from adjacent intersections. Guidelines for the application of regulatory and warning signs for highway traffic at LRT crossings are given in Chap- ter 10 of the MUTCD (2001). These signs could be adapted for use at intersections along at-grade busways on private rights-of-way or in street medians. 4-4 Examples of these signs are provided in Figures 4-2a and 4-2b. The symbols and wording have been modified to depict buses and busways instead of LRT vehicles and tracks. Their application should be generally consistent with applications set forth in the MUTCD. 4-3.2. Signal Displays Traffic signal displays and locations should be consistent with those set forth in the MUTCD as well as those specified by local agencies. The “Transit Signal” displays for LRT vehicles should be used for BRT, as appropriate. They are applicable where buses operate (1) along median arterial busways, (2) along at-grade busways on separate rights-of- way, and (3) in queue bypass lanes. The rationale is that BRT vehicles are, in essence, rubber-tired LRT vehicles. Exam- ples of these signal displays are shown in Figure 4-3. BRT traffic signals should be separated horizontally and vertically from general traffic signals by a distance of at least 3 feet. 4-4. SIGNAL PRIORITIZATION Bus delays at traffic signals account for 10 to 20% of over- all bus travel times and 50% or more of all delays. Therefore, adjusting signal timing to expedite BRT, as well as general A C B D Contra flow lane Route without contra flow lane (SOURCE: Webster and Bly, 1976) One-way traffic flows Two-way traffic flows Bus route with no contra flow lane Contra flow lane Figure 4-1. Hypothetical network for one-way streets.

traffic flow, will improve bus speeds and reliability. The underlying philosophy is to minimize overall person delay. However, adjustments to favor BRT, which are often desir- able, must be done selectively and carefully. Traffic signal controls for BRT include passive, active, and real-time priorities as well as preemption (examples of each are provided in Table 4-3) (Final Report, 2001; Shen et al., 1998): • Passive priority techniques are designed to improve BRT speeds by modifying existing signal operations. Signals should be timed to minimize delays to buses by adjusting the signal cycle length and split, by minimiz- ing the number of phases, by using short cycle lengths 4-5 when practical, and by maximizing the green times along BRT routes. • Special phases can be provided for BRT where they conflict with other movements. They can be pre-timed or actuated. • Active priority techniques adjust the signal timing after a bus is detected. They can advance or extend the artery green time for oncoming buses within the established signal cycle. • Real-time techniques consider both automobile and bus arrivals at a single intersection or a network of intersec- tions. Applications have been limited to date and require specialized equipment. R15-5b R15-5a DO NOT PASS STOPPED BUS W10-7b Activated Blank-Out I-12b W10-2b W10-4bW10-3b W10-1 BUS WAY (SOURCE: Adapted from Manual on Uniform Traffic Control Devices for Streets and Highways, Millennium Edition, 2001) Figure 4-2a. Traffic signs for BRT.

• Preemption results in changes to the normal signal phas- ing and sequencing to provide a clear path for oncoming buses. Because of its impacts to both signal coordination and pedestrian safety, it must be very carefully applied. 4-4.1. Passive Signal Priorities Passive signal priorities improve BRT speeds by modify- ing signal operation within the established signal systems to be more responsive. 4-4.1.1. Number of Phases The number of phases should be as few as possible. Basic two-phase operations should be encouraged, and complex multi-phase operations should be avoided. This calls for careful consideration of intersection geometry, traffic con- 4-6 trols, and signal phasing. Exclusive pedestrian phases should be the exception rather than the rule. Median arterial busways will require additional phases to avoid turning conflicts between buses and automobiles. In these cases, longer cycle lengths will be needed to accom- modate conflicting movements and to provide sufficient time for pedestrians crossing the artery. Some considerations for phasing are the following: • Traffic signal sequences should have the artery left-turn phase follow the through phase along the artery. This is essential to avoid same-direction sideswipes—an acci- dent problem that was reported along several median- aligned LRT lines. The suggested sequence of signal phases is shown in Figure 4-4. • An additional lane should be provided within the busway for buses making left turns at signalized inter- sections. The signal phasing should provide a bus- actuated protected movement for the buses turning left. (SOURCE: Adapted from Manual on Uniform Traffic Control Devices for Streets and Highways, Millennium Edition, 2001) R3-1a Activated Blank-Out R3-2a Activated Blank-Out R15-6b R15-6b DO NOT DRIVE ON BUSWAY R15-7 R15-7a R15-8 R10-6R8-8 DO NOT STOP ON BUSWAY Figure 4-2b. Additional traffic signs for BRT.

Special signal phases are required in special circum- stances. Some illustrative examples of special bus phases are shown in Figure 4-5. The special phases can be actuated (or preempted) when buses arrive, or they can operate pre-timed. Except for isolated locations, the special phases should be part of overall background cycles. 4-4.1.2. Cycle Lengths Cycle lengths should accommodate peak traffic flows, let pedestrians cross safely, allow a reasonable allocation of 4-7 green time among conflicting flows, and permit coordina- tion at desired speeds. Within this context, cycle lengths should be as short as possible along BRT routes. A good practical range is 60 to 90 seconds. Longer cycles (up to 120 seconds) should be limited to major multilane arterial intersections, bridge approaches, expressways, and com- plex multi-leg intersections. Longer cycles may sometimes be appropriate during peak periods to provide more arterial green time, to permit longer platoons, and to reduce the number of start-up delays. The shorter cycles have the effect of reducing red times for buses—especially in bus lanes. For a 60-second cycle, (2) (1) (1),(2) Flashing (1) (1),(2) (1) (1),(2) Flashing Three-Lens Signal Two-Lens Signal STOP PREPARE TO STOP GO SINGLE LRT ROUTE TWO LRT ROUTE DIVERSION Flashing Flashing STOP GO THREE LRT ROUTE DIVERSION NOTES: All aspects are white. (1) Could be in single housing. (2) "Go" lens may be used in flashing mode to indicate "prepare to stop." (SOURCE: Adapted from Manual on Uniform Traffic Control Devices for Streets and Highways, Millenium Edition, 2001) One-Lens Signal Figure 4-3. Typical LRT signals applicable to BRT.

4-8 SUGGESTED TRAFFIC SIGNAL SEQUENCE FOR MEDIAN ARTERIAL BUSWAYS NOTE: BRT phases may be pre-timed or actuated Transitway BRT Median Busway BRT A B C Figure 4-4. Suggested traffic signal sequence for median arterial busways. Treatment Description Passive Priority Adjust Cycle Length Reduce cycle lengths at isolated intersections to benefit buses Split Phases Introduce special phases at the intersection for the bus movement while maintaining the original cycle length Areawide Timing Plans Preferential progression for buses through signal offsets Bypass Metered Signals Buses use special reserved lanes, special signal phases, or are rerouted to nonmetered signals Adjust Phase Length Increased green time for approaches with buses Active Priority Green Extension Increase phase time for current bus phase Early Start (Red Truncation) Reduce other phase times to return to green for buses earlier Special Phase Addition of a bus phase Phase Suppression Skipped nonpriority phases Real-Time Priority Delay-Optimizing Control Signal timing changes to reduce overall person delay Network Control Signal timing changes considering the overall system performance Preemption Current phase terminated and signal returns to bus phase TABLE 4-3 Bus signal priority systems the likely maximum red time is 30 seconds, for multi-phase operations on a 120-second cycle, the red times would be 60 to 80 seconds. This finding has also been reported in the United Kingdom (Gibson, 1996). Cycle lengths of 50, 60, 72, 75, 80, 90, 100, and 120 sec- onds result in an “even” number of cycles per hour. This enables BRT vehicles to be scheduled at the same time on a cycle-to-cycle basis each day. 4-4.1.3. Intersection Timing The green times along BRT routes should be maximized. Intersection timing should consider the relative numbers of people moved per lane on each intersecting street rather than merely the vehicle movements. This translates into provid- ing as much green time as possible along BRT routes, while still providing sufficient green time for pedestrians crossing the BRT artery. This approach contrasts with the traditional method of signal timing that considers the time needed by pedestrians to cross each street at the intersection, the time needed by traffic on each intersection approach, the individ- ual phase requirements, and the relation to other signalized locations along the street. 4-4.1.4. Coordination Traffic signals along a BRT route should be coordinated where signals are 1 mile apart or less. Coordination is most

effective when signals are spaced at uniform intervals. In some cases (as along streets with heavily used bus lanes), the signals can be set for buses. This practice is followed in downtown Ottawa where bus speeds average 9 miles per hour (as com- pared with 5 to 6 miles per hour in other city centers). 4-4.2. Active Signal Priorities Active bus priorities at traffic signals extend or advance the green time for oncoming buses within the established cycles. Thus, they can further reduce BRT travel times and running time variability. These priorities are especially applic- able when buses operate in mixed traffic. They will also ben- efit BRT operations in bus lanes and median arterial busways. As with other BRT priority treatments, the total person minutes saved by BRT and other vehicles along the artery should outweigh the increased delays to people in vehicles 4-9 on intersecting streets. More specifically, increases in green time achieved by advancing or extending the green light are desirable whenever the following conditions apply: • The person minutes saved by bus and automobile pas- sengers along the BRT artery exceed the person minutes lost by side street automobile drivers and passengers, • Side street green time can be reduced and still provide adequate clearance time for pedestrians, and • Increased queues on side streets will be manageable. 4-4.2.1. Description BRT vehicles can get preference at signalized intersec- tions by advancing or extending the artery green time. Buses are detected as they approach the intersection by various detec- tion technologies. This information is then transmitted to the 1. BUSWAY- CROSS STREET 2. BUSWAY- COMPLEX JUNCTION 3. TURNS FROM MEDIAN ARTERIAL BUSWAY BRT BRT BRT BRT 4. ACCESS TO BUS TERMINAL OR TURNAROUND NOTE: BRT phases may be pre-timed or actuated BRT TURN-AROUND/ TERMINAL POSSIBLE DETECTOR Figure 4-5. Examples of special bus phases.

master and local traffic signal controllers. Chapter 7 provides technical details on various vehicle detection technologies and their relation to AVL. Bus detection should take place before buses reach the stop line. When the detection occurs during the artery green time, the artery green is extended to enable buses to clear the signal. If the detection occurs during the yellow (clearance) or red intervals, the green time can be recalled in advance of its normal time. These timing adjustments reduce the maxi- mum delay time to buses by reducing the red interval. The basic transit priority concept is shown in Figure 4-6. The modifications of artery green time are done within the prevailing traffic signal cycle to maintain artery coordination and to prevent successive signals along a street from operat- ing on different cycle lengths. Guidelines for active signal priorities include the following: • A minimum side street green is required in each cycle. It must provide adequate time for pedestrians to cross the artery. • The artery green may be advanced up to a specified period before it takes place or extended up to this amount after it takes place. • The artery green should not be advanced and extended in the same cycle. The extent that the artery green time can be increased will depend on the side street volumes, coordination requirements, prevailing cycle lengths, and artery roadway width. The effects of these factors on the additional green times are illustrated in Figure 4-7. The green time can be increased the most at loca- tions where cross street volumes are light, but increases may have to be limited at major intersecting streets. Increases in queues on cross streets should be kept to a minimum. When buses arrive every cycle or move frequently, it may be desir- able to limit the amount of additional green time to avoid queue buildup on intersecting streets. 4-4.2.2. Bus Priority (Preferences) Bus priority at traffic signals can reduce transit travel times and running time variability. Generally, about a quarter to a third of transit delays in central areas are attributed to signals. Priority at traffic signals is applicable especially when buses or BRT operate in mixed traffic and when it is not practical to pro- vide bus-only lanes. Priority also can be provided for bus lanes and at-grade busways. However, when buses arrive every cycle (or more frequently), the amount of the additional green time should be limited to avoid queue buildup on intersecting streets. Heavy pedestrian volumes, major (sometimes equal) inter- secting bus volumes, and frequent intersection spillback will limit the benefits of bus priority at traffic signals in the city center. Consequently, the best potential for active signal pri- ority is along arterial BRT routes at locations where side street progression is not a significant factor. There is a relatively narrow range within which the green time can be adjusted in most cases. In Los Angeles, for exam- ple, the maximum additional green time is 10% of the signal cycle. Bus delays were reduced with negligible impacts to cross street traffic. The City of Los Angeles reported that bus headways should not be less than 2.5 to 3.0 minutes to enable major cross streets to recover from the time lost (Final Report, 2001). These green (and red) time adjustments can be fine- tuned to minimize total person delays. 4-4.2.3. Control Strategies Several different control strategies can be used to reduce the maximum delay time to buses by reducing the red inter- val. They may be conditional (whenever the bus arrives in the designated window) or unconditional (subject to certain con- straints). Examples of strategies are provided in Table 4-4. See Chapter 7 for further technical details. Some control strate- gies are the following: 1. Buses can receive the additional green time when- ever they arrive within the specified green time window (unconditional). 2. Buses can receive the additional green time only when they are late. This requires integration of the signal detec- tion with an automatic vehicle location and control sys- tem (conditional). 4-10 (SOURCE: Levinson et al., 1975) NOTE: A. The minimum side street green is required each cycle. B. If the Artery green is advanced, it should not be extended in the same cycle, but C. If the Artery green is extended, it should not be advanced in the next cycle. D. Yellow intervals are not shown Figure 4-6. Bus signal priority concept.

(SOURCE: Levinson et al., 1975) Figure 4-7. Bus signal priority concepts for arterial streets. 4-11 Element Examples of Possible Strategies Pedestrian clearance interval Allow pedestrian interval and clearance intervals to expire before changing phases Conflicts with emergency vehicles Allow emergency vehicles to override bus priority request Minimum green interval of current phase Allow minimum green interval to clear for phase in operation before changing phase to favor bus Highly Desirable Yellow change interval and all-red clearance interval Allow yellow change interval and all-red clearance intervals to clear before changing signal to green for bus Selective response to buses Provide priority only to buses running behind schedule Frequency of response to bus priority calls Once a bus has received priority treatment, will not provide priority treatment to other buses until one full cycle has elapsed; may not allow priority response more often than every other cycle. Length of time to hold green light for bus Will not extend green for buses beyond maximum green interval allocated to that phase Optional Effect of signal priority on signal coordination After bus priority call handled, traffic signal returns to its coordination scheme within 30 seconds, even if signal must skip a phase SOURCE: Rutherford et al., 1995. TABLE 4-4 Elements of signal priority control systems

3. Advances and extensions can be more frequent than every other cycle only when buses are late. This requires tying the signal detection to the master traffic signal control computer, as is done along Wilshire and Whittier Boulevards in Los Angeles. 4. New multi-phase (e.g., Type 2070) controllers can provide additional green time for buses in each signal phase. This is achieved by providing special “next phase” software in each local intersection controller. A schematic portrayal of this concept as compared with the traditional application is shown in Figure 4-8. This concept has been used on the Salt Lake City LRT line. It is applicable when BRT operates within median arte- rial busways and other at-grade busways (conditional or unconditional). 4-4.3. Signal Priorities for Queue Bypasses and Gating Active traffic signal priorities can be used in conjunction with queue bypass bus lanes to reduce delays and to facilitate reentry into the traffic stream. On arterial roads where there is not enough space for a bus lane for the entire length of the road, several agencies have installed queue bypasses. Short lanes leading to the intersection are added so that the transit 4-12 vehicles can bypass the queue of automobiles and get to the front of the line. This technique can be enhanced by using signal queue jumps, which allow the transit vehicles a few seconds head start on the rest of the vehicles at the intersection. Buses are allowed to reenter the regular lanes in front of the other vehi- cles, thereby preventing bottlenecks downstream of the inter- section. These lanes are found in several U.S. urban areas, including Seattle and San Diego. In Seattle, a short curb queue bypass lane is located on Pacific Street and Montlake Boule- vard, near the University of Washington. A bus-only queue bypass operates on downtown Second Avenue as part of a multi-block bus lane. An advance green signal is also provided for the Airport Road HOV lane in Snohomish County. In San Diego, a bus bypass lane at a signalized intersection in the Mission Valley area is located between the right-turn lane and the general purpose lane (Rutherford et al., 1995). In conjunction with queue bypass bus lanes, it is desirable to provide a bus-actuated advance green indication of about 5 to 10 seconds for buses. To avoid motorist confusion, the standard “Transit” signals should be used for bus movements. Bus priority gating is a technique related to signal queue bypasses. This technique stops non-priority traffic short of the intersection while the priority traffic (buses) proceeds to the main stop line. As the signal turns green, the buses pro- ceed ahead of non-priority traffic. Bus priority gating is used in a few cities in Great Britain and in Berne, Switzerland. A bus advance area before the main signalized intersection is used to store buses and give them entry into the main inter- section in advance of queued traffic. A set of pre-signals holds general purpose traffic, allowing buses to advance around the general traffic queue. Bus priority gating and advance areas can accomplish several objectives: (1) they can be used when a bus lane is ending to enable buses to reenter the traffic stream, (2) they can be used to allow buses to jump to the front of a queue at a traf- fic signal after they have picked up passengers at a bus stop, and (3) they can allow buses to jump ahead of other traffic to cross over lanes to reach the left-turn lane without obstruction. Figure 4-9 shows how gating can facilitate buses making left turns from a curb bus lane on approaches to an inter- section. The advance area should be able to store at least two buses per cycle (e.g., about 100 to 150 feet). The block spac- ing between street intersections should be at least 400 feet. The artery traffic signals for general purpose traffic would be green at the same time at both intersections. On actuation, the bus lanes would get the green indication during the phase in which the cross-street traffic moves. 4-5. ENFORCEMENT The success or failure of a BRT project is critically depen- dent on keeping running ways clear of improper use by auto- TRADITIONAL ADVANCE AND EXTENSION NEXT PHASE PREFERENCE FOR BUSES B B B B B B B B 1 12 Extension Cycle Advance 3 1 11 2 Advance Special WindowExtension Figure 4-8. Traditional and next phase signal preference concepts.

mobiles, taxis, and trucks. Public perceptions of violations can ultimately affect the respect and support for BRT. There- fore, effective enforcement and monitoring of BRT running ways and traffic regulations are essential. 4-5.1. Enforcement Agencies Enforcement policies, programs, and activities involve various groups and agencies. These groups include state DOTs, transit agencies, state and local police, state and local judicial systems, local municipalities, metropolitan planning organizations, rideshare agencies, and federal agencies. Key elements of enforcement activities include the following: • Legal authority, • Citations and fines, • General enforcement strategies, 4-13 • Specific enforcement technologies, • Funding, and • Communication techniques. Enforcement should be done by the jurisdictions that have primary responsibility for the BRT facility. Typically, munic- ipal police monitor city streets, and state police monitor freeway-related facilities. However, it may be desirable for special transit agency police to enforce busways and other running ways. The type of enforcement will depend on the specific running way treatment. Examples of enforcement problems and potential approaches for various types of run- ning way are given in Table 4-5. Some running way designs are deterrents by themselves because of the different types of operations and driving behav- iors. Tolerable violation rates on urban streets should be much lower than those on limited-access highways; to accomplish this, urban streets will require more rigid enforcement than busways. 4-5.2. Enforcement Strategies Past studies have classified enforcement strategies by highway and police patrols into one of three categories: rou- tine enforcement, special enforcement, or selective enforce- ment. Routine enforcement is randomly conducted, whereas special enforcement entails specific planning including team patrols and roving or stationary enforcement patrols. Selec- tive enforcement combines the two strategies and may focus on problem locations. The latter two strategies are only con- ducted on a short-term basis because of their high cost, and they may not have an immediate impact on violation rates. A passive approach has patrols reroute violators to a more cir- cuitous route; violators thereby encounter a travel-time penalty in their trips. To facilitate enforcement, special enforcement areas should be located along BRT bus lanes where space exists. Video surveillance of violators is desirable. Enforcement of bus lanes should include both fines and towing. Fines for illegal use of bus lanes and curb parking violations should be set at high levels (e.g., $50 to $250 per violation). There should be an aggressive towing program for illegally parked vehicles along bus routes and in bus lanes. Immediately towing and impounding violating vehicles has proven effective. Another means for managing violators of restricted lanes is through penalties and public awareness. In addition to levying fines, some states give penalty points that are put against a driver’s record. Public outreach, such as posting penalty infor- mation on signage, also has been used to educate motorists about regulations along the targeted roadways. The California DOT found that the number of citations declined by 61% when fines were posted. Locat ion 2 Locat ion 1 Locat ion 2 Locat ion 1 SIGNAL PHASING BUS Figure 4-9. Signal priority for left turns from right curb bus lane.

In the greater Houston, Seattle, and Washington, D.C./ Northern Virginia areas, the “HERO” program has become an important part of bus and HOV lane enforcement and public education. This program allows witnesses to call and report violators of the restricted lanes. At the same time, “HERO” provides the opportunity to educate violators. An initial evaluation report in Seattle indicated a one-third reduc- tion in violation rates after the “HERO” program was estab- lished. The proliferation of cellular phone use has made this program even more effective. 4-5.3. Enforcement Technologies Various technologies can be employed for monitoring and enforcement. Some strategies use TV monitors to direct enforcement. Another, perhaps more controversial, form of enforcement uses Photocop applications, in which violators receive a picture and fine in the mail. (Rutherford et al., 1990). The use of ITS sensors as an enforcement technology is also being explored. This technology usually relies on auto- matic vehicle identification (AVI). A pilot system in Dallas, the HOVER system, showed promise by using a combination 4-14 of AVI, video cameras, and infrared machine technologies. Portland, Oregon, has conducted an operational test of AVI, in which registered car pools and buses are issued vehicle identification cards that are read at entrance ramps. Northern Virginia and California apply various audio and video tech- niques to detect violations and then issue citations by mail. The Texas Transportation Institute is investigating ways of using roadside readers. The Georgia Institute of Technology is studying methods that use scanning radiometers to deter- mine the number of people in automobiles. These ITS-related strategies are mainly applicable on busways and freeway bus lanes. Use of colored pavements (e.g., green in New Zealand and Ireland, yellow in Brazil and Japan, and maroon in France) has been shown to ease enforcement problems. 4-6. CHAPTER 4 REFERENCES Final Report, Los Angeles Metro Rapid Bus Demonstration Program. Los Angeles County Metropolitan Transit Authority, Los Angeles, CA (July 2001). Gibson, J. “Effects of a Downstream Signalized Junction on the Capacity of a Multiple Berth Stop.” Proc. 24th PTRC European Transport Forum. London, United Kingdom (September 2–6, 1996). Treatment Typical Violations Enforcement Strategies Public education and heavy enforcement Identification and enforcement of upstream violators Use of closed left-turn bays for patrol-car observations as apprehension areas Median lane, concurrent flow Unauthorized use of exclusive lane Illegal left turn across exclusive lane Transit marketing and good design for bus access to exclusive lane Illegal parking and stopping in bus lane Use civilian agents or provision of police incentives Unauthorized use of exclusive lane Public education and posting of fines Illegal left turns and crossing of contra flow lane Heavy initial enforcement and towing of parked vehicles Passive enforcement and travel-time penalty Special enforcement on opposite curb lane Bus lane, curbside concurrent flow Illegal pedestrian maneuvers Continuing enforcement Unauthorized use of bus lane Design features of self-enforcement Illegal left turns and crossing of contra flow lane by pedestrians Adequate lane markings and signing Median lane, contra flow Inattentive crossing of contra flow lane by pedestrians Concentrated enforcement at intersections Illegal parking, stopping, or standing Use of monitors for peak-hour enforcement Curb lane, contra flow Illegal pedestrian and bicycle movements Use of monitors for peak-hour enforcement, plus heavy fines and immediate towing to penalize violators. Unauthorized use of bus street Bus-only streets Illegal crossing by pedestrian Little enforcement required Transmitter held by unauthorized party Running of red light by motorists due to phase changes Signal preemption Running of red light by bus operator because of pre-anticipation of green phase Routine traffic enforcement measures SOURCE: Adapted from Rutherford et al., 1990. TABLE 4-5 Enforcement strategies for running ways

Levinson, H. S., C. L. Adams, and W. F. Hoey. NCHRP Report 155: Bus Use of Highways: Planning and Design Guidelines. Transportation Research Board, National Research Council, Washington DC (1975). Manual on Uniform Traffic Control Devices for Streets and High- ways, Millennium Edition (MUTCD). U.S. Department of Trans- portation, Federal Highway Administration, Washington, DC (2001). Pline, J. L. (ed.). Traffic Engineering Handbook (5th ed.). Institute of Transportation Engineers, Washington, DC (1999). Rutherford, G. S., R. K. Kinchen, and L. J. Jacobson. “Agency Practice for Monitoring Violations of High-Occupancy-Vehicle Facilities.” In Transportation Research Record 1280, Trans- portation Research Board, National Research Council, Wash- ington, DC (1990) pp. 141–147. 4-15 Rutherford, G. S., S. MacLachlan, K. Semple. Transit Implications of HOV Facility Design, WA-RP-3961-1. Prepared for Federal Transit Administration by Washington State Transportation Center, Seattle, WA (September 1995). Shen, L. D., et al. At Grade Busway Planning Guide. Center for Urban Transportation Research, Florida International Univer- sity, The State University of Florida at Miami, Miami, FL (December 1998). Webster, F. V., and P. H. Bly. Bus Priority Systems. (Published on behalf of the NATO Committee on the Challenges of Modern Society.) Transport and Road Research Laboratory, Berkshire, United Kingdom (1976).