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64 acquisition required. If a far-side bus pullout is provided, Reliability is as important to transit users and service added costs would be incurred. providers as travel time savings. Improved travel time consis- tency means that regular transit users enjoy the ability to begin their trips at the same time every day, and transit operators can Curb Extensions reduce the amount of recovery time built into their schedules, which can save O&M costs. The cost of a curb extension varies based on the length and width of the treatment, site constraints, and the specific design The likely benefits of median transitway and exclusive of the curb extension. In San Francisco, costs of existing curb transit lane operation depend on the length of the lane and the extensions have ranged from $40,000 to $80,000 each. Much amount of time saved. Observations included the following: of the cost is derived from the need to provide adequate drainage, which often requires re-grading the street and side- A small amount of time savings primarily results in walk and moving drains, manholes, street lights, signal poles, passenger benefits. street furniture, fire hydrants, and other features. As the travel time savings increases, it may reduce fleet requirements and operating costs. IMPACTS ON TRANSIT OPERATIONS A time savings of more than 5 min (on a typical trip) can affect mode choice, further increase ridership, and Transit preferential treatments will have an impact on three possibly encourage land development. major components of transit operations: (1) travel time, and (2) reliability, which will then have an impact on (3) capital Figure 45 illustrates these relationships for exclusive and operating cost savings. The impact on transit operations bus lanes. of the different types of transit preferential treatments are described as follows. Examples of travel time savings observed with certain arterial street bus lane treatments are shown in Table 20. Examples of improvements in bus lane reliability are shown Median Transitways and Exclusive Lanes in Table 21. The improved reliability is measured by the per- The primary reason to add dedicated transit lanes to an at-grade cent change in the coefficient of variation (standard deviation premium transit service is to improve travel times and relia- divided by the mean). bility over mixed-traffic operations. The benefits of reduced travel times for transit users and improvements in reliability are Transit Signal Priority traded off against increased travel times for other roadway sys- tem users and the potential diversion to other roadway corridors Tables 22 and 23 present the measured/estimated impacts of (with associated impacts) if the new dedicated arterial transit bus TSP in selected cities in North America on travel time, lanes are developed by removing general traffic lanes. reliability (schedule adherence), and operating costs, as well FIGURE 45 Degree of bus lane impacts [Source: TCRP Report 26 (16)].

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65 TABLE 20 TABLE 21 OBSERVED TRAVEL TIME SAVINGS OBSERVED RELIABILITY IMPROVEMENTS WITH ARTERIAL BUS LANES WITH ARTERIAL BUS LANES Savings City Street (minutes per mile) City Street Percent Improvement* Los Angeles Wilshire Blvd. 0.1 to 0.2 (a.m.) Los Angeles Wilshire Blvd. 12 to 27 0.5 to 0.8 (p.m.) Dallas Harry Hines Blvd. 1 New York City Madison Ave. 57 *Coefficient of variation multiplied by 100. Dallas Ft. Worth Blvd. 1.5 Source: TCRP Reports 26 and 90 (16,4). New York City Madison Ave. 43%* express bus (dual bus lanes) 34%* local bus San Francisco 1st Street 39%* local bus BRT vehicles along Vancouver's 98-B line have saved up to *Percent reduction in travel time. 1.5 min per trip (5). Source: TCRP Reports 26, 90, and 118 (16,4,5). Schedule adherence as measured by variability in bus travel times and arrival times at stops improves significantly with as the impacts of TSP on general traffic. Expected benefits TSP application. In Seattle, along the Rainier Avenue corridor, of TSP vary depending on the application and the extent to bus travel time variability has been reduced by 35%. In Port- which the signal system in a particular area already has land, TriMet was able to eliminate one bus assignment to one optimized progression before TSP application. A summary of of its corridors by using TSP and has experienced up to a 19% these impacts follows. reduction in travel time variability in certain corridors. In Van- couver, the travel time variability along its BRT routes has Travel time savings associated with TSP in North America decreased approximately 40%. and Europe have ranged from 2% to 18%, depending on the length of corridor, particular traffic conditions, bus opera- By reducing bus travel time and delay and the variability tions, and the TSP strategy deployed. A reduction of 8% to in travel time and delay, transit agencies have realized both 12% has been typical. The reduction in bus delay at signals capital cost savings (by saving one or more buses during the has ranged from 15% to 80%. length of the day to provide service on a route) and operat- ing cost savings (owing to more efficient bus operation). In In Los Angeles, in the initial WilshireWhittier and Ven- Los Angeles, the MTA indicated that before the Wilshire tura BRT corridors, average running time along both corridors Whittier and Ventura BRT implementation, the average cost associated with TSP decreased by 7.5%. This corresponds to of operating a bus was $98 per hour. A traffic signal delay an average decrease of 0.5 min per mile on WilshireWhittier reduction of 4.5 min per hour translates into a cost savings of Boulevard and a decrease of 0.3 min per mile on Ventura approximately $7.35 per hour per bus for the initial two BRT Boulevard. The reduction in bus signal delay at intersections corridors. For a bus operating along these corridors for 15 hours with TSP was 33% to 36%. In Chicago, buses have achieved a day, the cost savings would be approximately $110.25 per an average 15% reduction in running time along Cermak day. Assuming 100 buses per day for an average of 300 days Road, with the reductions varying from 7% to 20% depending per calendar year in the two corridors, this translates into on the time of day. Along San Pablo Avenue in Oakland, each an approximately $3.3 million annual operating cost savings bus has saved an average of 5 s per intersection with TSP. for the MTA. This savings does not include the added benefit TABLE 22 REPORTED INITIAL ESTIMATES OF BENEFITS TO BUSES FROM TRAFFIC SIGNAL PRIORITY % Reduced % Running Time % Increase in Intersection Location Saved Speeds Delay Anne Arundel County, MD 1318 -- -- Bremerton, WA 10 -- -- Chicago, IL--Cermak Road 1518 -- -- Hamburg, Germany -- 2540 -- Los Angeles--Wilshire/Whittier 810 -- -- Metro Rapid Pierce County, WA 6 -- -- Portland, OR 512 -- -- Seattle, WA--Rainier Avenue 8 -- 13 Toronto, ON 24 -- -- Source: TCRP Reports 90 and 100 (4,3), FTA CBRT Document (32).

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66 TABLE 23 ITS AMERICA'S SUMMARY OF TSP BENEFITS AND IMPACTS--BUS AND RAIL No. of Transit Inter- TSP Location Type sections Strategy Benefit/Impact Portland, Bus 10 Early green, Bus travel time savings = 1.4%6.4%. Average OR--Tualatin green bus signal delay reduction = 20%. Valley Hwy. extension Portland, Bus 4 Early green, 5%8% bus travel time reduction. Bus person OR--Powell green delay generally decreased. Inconclusive impacts Blvd. extension, of TSP on traffic. queue jump Seattle, Bus 1 Early green, For prioritized buses: WA--Rainier green 50% reduction of signal-related stops Ave. at extension 57% reduction in average signal delay Genesee 13.5% decrease in intersection average person delay. Average intersection delay did not change for traffic. 35% reduction in bus travel time variability. Side-street effects insignificant. Seattle, Bus 3 Early green, For TSP-eligible buses: WA--Rainier green 24% average reduction in stops for eligible Ave. (mid- extension buses day) 34% reduction in average intersection delay 8% reduction in travel times. Side-street drivers do not miss green signal when TSP is granted to bus. Toronto, ON Street- 36 Early green, 15%49% reduction in transit signal delay. One car green streetcar removed from service. extension Chicago, Bus 15 Early green, 7%20% reduction in transit travel time. Transit IL--Cermak green schedule reliability improved. Reduced number Rd. extension of buses needed to operate the service. Passenger satisfaction level increased. 1.5 s/vehicle average decrease in vehicle delay. 8.2 s/vehicle average increase in cross-street delay. San LRT 16 Early green, 6%25% reduction in transit signal delay. Francisco, and green CA Trolley extension Minneapolis, Bus 3 Early green, 0%38% reduction in bus travel times MN-- green depending on TSP strategy. 23% (4.4 s/vehicle) Louisiana extension, increase in traffic delay. Skipping signal phases Ave. actuated caused some driver frustration. transit phase Los Angeles, Bus 211 Early green, 8% reduction in average running time. 35% CA-- green decrease in bus delay at signalized intersections. Wilshire and extension, Ventura actuated Blvds. transit phase Source: An Overview of Transit Signal Priority, ITS America (21). of travel time savings for the Rapid Bus passengers. With tions, including 27 with TSP operation, has seen a significant an anticipated project life cycle of 10 years, the relative reduction of almost 50% in signal delays during the weekday benefitcost ratio for TSP associated with the Wilshire a.m. and p.m. peak periods, and a slightly lower delay reduc- Whittier and Ventura BRT corridors was estimated to be tion during the off-peak period. Similarly, the Carlton street- greater than 11:1 (5) car has experienced a major reduction in intersection delay with TSP ranging from 21% to 28%. The variability in TSP Several studies of the streetcar system in Toronto (24) travel time savings across routes results from the variation on found TSP to be beneficial, with reductions identified in the percent of intersections with near-side stops, service fre- streetcar travel times and improvements in on-time perfor- quency, degree of separation from traffic, length of route, and mance. The streetcar as a whole has experienced reductions in ridership increase following TSP implementation. The ser- travel times of between 6% and 10%. This is based on a sys- vice reliability improvements associated with TSP on the tem with only 77% of signals operating TSP. The Dundas streetcar system have included a reduction in vehicle bunch- streetcar line, which travels through 31 signalized intersec- ing and headway variability.

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67 Queue Jumps and Bypass Lanes TABLE 24 AVERAGE BUS CLEARANCE TIME By allowing a transit vehicle to bypass general traffic queuing (Random Vehicle Arrivals) at a signalized intersection, transit travel time is reduced with Adjacent-Lane Mixed- improved service reliability. The extent of transit travel time Traffic Volume Average Re-Entry (vehicles/hour) Delay (seconds) savings will depend on the extent of general traffic queuing at 100 1 a signalized intersection, the extent to which a bypass treat- 200 2 ment can be developed to bypass the general traffic queue, 300 3 and the magnitude of right-turn traffic if the queue bypass 400 4 500 5 uses such a lane (and also whether or not free right turns are 600 6 allowed from the right-turn lane). With either a queue jump or 700 8 bypass lane some increase in delay to right-turn traffic could 800 10 occur if a separate lane for buses is not provided. Transit 900 12 1,000 15 travel time savings are reduced if the right-turn lane traffic volume is heavy and there is limited opportunity for free right Source: TCRP Report 100 (3). Computed using Highway Capacity Manual 2000 (19) unsignalized intersection turns or right turns on red. methodology (minor street right turn at a bus stop) assuming a critical gap of 7 s and random vehicle Application of bus queue jumps has been shown to produce arrivals. Delay based on 12 buses stopping per hour. 5% to 15% reductions in travel time for buses through inter- sections. Service reliability is improved because of reduced bus delay at signals. Reported travel time savings associated service reliability also can be improved. At the same time, pro- with queue jumps and/or bypass lanes are as follows (5): vision of a near-side curb extension precludes the ability to provide a dedicated right-turn lane at an intersection. 7- to 10-s bus intersection delay savings on Lincoln Street at 13th Avenue in Denver. By reducing bus travel time, some operating cost savings 27 s reduction in bus travel time along the NE 45th Street can be achieved with curb extensions if implemented in a sys- route in Seattle during the weekday a.m. peak period. tematic manner. 12 s reduction in bus travel time along the NE 45th Street route in Seattle during the weekday p.m. peak period in An extensive evaluation of the impact of curb extensions Seattle. on transit operations was conducted in 1999 as part of a proj- 6 s reduction in bus travel time along the NE 45th Street ect along Mission Street in San Francisco to convert bus bays route in Seattle across an entire day. to bus bulbs. As part of the TCRP A-10A project on Evalua- tion of Bus Bulbs (8), a before-and-after study was under- By reducing bus travel time, some operating cost savings taken at the bus stop locations along Mission Street. The study can be achieved with queue jumps and/or bypass lanes revealed about a 7% increase in bus operating speeds along if implemented in a systematic manner, particularly if the the corridor. The study also assessed the change in pedestrian cumulative effect were the elimination of a bus to meet the flow rates next to one of the bus stops with the added pedestrian service need. area associated with the provision of a bus bulb versus the orig- inal sidewalk with a bus bay. The study revealed an average 11% improvement in pedestrian flow rate (ped/min/ft) during Curb Extensions the peak 15-min periods evaluated. By allowing a bus to stop in the general traffic lane and not The TCRP A-10A study also conducted a simulation analy- have to pull over to a curb at a bus stop, travel time is reduced sis in a corridor in San Francisco to evaluate the impact of bus by eliminating "clearance time." This is the time a bus waits to bulbs on transit and general traffic operations. The simulation find an acceptable gap in the traffic stream so that the bus can runs included both far-side and near-side bus stops, and bus pull back into the general traffic lane. The clearance time bays and bus bulbs. For near-side stops, it was determined depends on the adjacent lane traffic volume and bus operator that the bus bulb design is beneficial over the bus bay design experience, and various studies have shown that clearance with respect to average traffic speeds at lower volumes (below times can range from 9 to 20 s. 1,000 vehicles/h), regardless of the bus dwell time. For far-side stops, it was determined that there was no practical difference Table 24 identifies clearance times associated with differ- in average traffic speeds. ent adjacent-lane mixed-traffic volumes under particular bus operating conditions, based on research conducted in develop- ing TCRP Report 100 (3). A volume range of 0 to 1,000 vehi- Stop Consolidation cles per lane per hour typically results in an average bus clear- ance time of 0 to 15 s. By eliminating clearance time through Research was undertaken as part of TriMet's bus stop con- curb extension application, the variability of dwell time at solidation program to try to quantify the travel time savings stops along an arterial corridor can be improved and, thus, bus associated with implementation of stop consolidation in a