A before-and-after study found that transit patrons experienced a smoother and more comfortable ride when a transit signal priority system was implemented in Seattle, Washington.
Date Posted
04/10/2002
Seattle, Washington, United States
Seattle,
Washington,
United States
Identifier
2002-B00232
Effectiveness of Bus Signal Priority: Final Report
Summary Information
This study evaluated the impacts of transit signal priority (TSP) on traffic operations based on literature research and testimonial interviews with ten traffic engineers and planners at several state agencies. The goal of this study was to compare various TSP options and provide deployment guidelines to assist transportation agencies in deploying viable signal control strategies. Both quantitative and qualitative data were provided as well some high-level system cost information.
SEATTLE, WASHINGTON
In the spring of 2000, the King County DOT implemented a 2.1 mile signal priority system on Rainier Avenue. The system used in-vehicle radio frequency transponders, roadside antennas, and transit priority request generators. The system was designed to control signal timings according to the following logic:
Major findings of the study showed intersection delay was reduced by an average of 13 percent (2.3 seconds per vehicle) during the AM peak period. In addition, minor traffic movements on side streets, and in left turn lanes off the main street showed intersection delay reductions of 3 percent (0.9 seconds per vehicle). During the midday peak, intersection delay increased slightly; however, level-of-service remained the same.
In general, before and after studies conducted by King County Metro found transit patrons experienced a smoother and more comfortable ride.
In the spring of 2000, the King County DOT implemented a 2.1 mile signal priority system on Rainier Avenue. The system used in-vehicle radio frequency transponders, roadside antennas, and transit priority request generators. The system was designed to control signal timings according to the following logic:
- Approaching priority vehicles were granted extended green intervals and shortened red displays; however, signal coordination between intersections had to be maintained, and the phase cycles for adjacent traffic could not be skipped.
Major findings of the study showed intersection delay was reduced by an average of 13 percent (2.3 seconds per vehicle) during the AM peak period. In addition, minor traffic movements on side streets, and in left turn lanes off the main street showed intersection delay reductions of 3 percent (0.9 seconds per vehicle). During the midday peak, intersection delay increased slightly; however, level-of-service remained the same.
In general, before and after studies conducted by King County Metro found transit patrons experienced a smoother and more comfortable ride.
Effectiveness of Bus Signal Priority: Final Report
Effectiveness of Bus Signal Priority: Final Report
Source Publication Date
01/02/2002
Publisher
Florida DOT and the U.S. DOT
Other Reference Number
Report No. CTR-416-04
Taxonomy (ARC-IT)
Public Transportation »
Transit Signal Priority (PT09)
Goal Areas
Deployment Locations
