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3rd Street Light Rail. Process and Challenges of Developing Transit Signal Priority. Javad Mirabdal, Jack Fleck & Britt Thesen Department of Parking and Traffic City and County of San Francisco October 22, 2003. Outline. Project Background Existing Conditions General Project features
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3rd Street Light Rail Process and Challenges of Developing Transit Signal Priority Javad Mirabdal, Jack Fleck & Britt Thesen Department of Parking and Traffic City and County of San Francisco October 22, 2003
Outline • Project Background • Existing Conditions • General Project features • Timeline and Goals • Transit Priority • Software selection process • Vissim Modeling • Results • Lessons Learned
Existing Conditions • 5.4 mile corridor • 35 signalized intersections • 3 traffic lanes in each direction with parking • Serviced by MUNI’s 15 Bus line • 7 to 15 minute headways • Current ridership: 25,000
General Project Features – Phase 1 • 65 signalized intersections • 19 stations • 2 traffic lanes in each direction with left turn pockets at some locations • Most blocks have parking, with parking removed near stations and left turn pockets • Exclusive Right of Way except Bayview Commercial Core and 4th St. Bridge • Transit Signal Priority & Preemption • Funding: $520 million, Local Sales Tax
Intial Phase General Project Features – Phase 2 • New Central Subway to Chinatown • Funded by Federal Match • Currently in Conceptual Engineering • 4 Underground Stations • New Central Subway to Chinatown • Funded by Federal Match • Currently in Conceptual Engineering • 4 Underground Stations
Project Goals • Improve Transit Service along Corridor • Reduce travel time and delay • Increase ridership • Connect Southeast SF to Downtown • Transit Oriented Development • Economic Revitalization
TSP Elements • 2070 (TS2) Signal Controllers with Transit Preemption/Priority capabilities • Fiber Optic Cable for Communication • Linked to Central Traffic Management Center (SFgo) • Vehicle Detection System: Video (Autoscope) • LRV Detection System: VETAG
Transit Priority Vision • Trains travel station to station without stopping! • Progression on 3rd Street essentially maintained • No phase waits more than 1 cycle (90 sec) • Side Streets, Left turns and Pedestrians are actuated • Pedestrians receive enough time to cross street at 4 ft/sec, or 2.5 ft/sec if phase is actuated
Transit Priority Strategies • Skip Phases • Extend Phases • Shorten Side Street Phases • Lead/Lag (phase rotation) • Early Green • Get Back in Step within 1 Cycle
Software Selection Challenges • Meet technical requirements city-wide implementation (more than 2 rings, communication over ethernet, etc.) • Transit Priority and Preemption Features • Easy to learn, implement and maintain • Good technical support
Software Wish List • General Features • Pedestrian Features • Transit Priority • General Preemption • Cable Car Preemption • Coordination • Communications (full list available upon request)
Software Selection Process • Evaluated options • Narrowed field down to • NextPhase (4-ring software) • VS-Plus (Matrix software, no rings or barriers) • Modeled softwares in VISSIM for comparison
Software Selection Process: VISSIM Model • Micro-level simulation • Runs virtual signal controllers for each intersection • Very time consuming to build model but… • Powerful modeling capabilities -pedestrians, bikes, right turn conflicts, trains, passenger loading, etc.
VISSIM Modeling Process CesarChavez • Test section of 7 intersections • Nextphase, VS-PLUS, and fixed time conditions • Modeled different train headways • Multiple runs of each model with random arrivals, driver behavior, etc. to get more realistic results Cargo Evans
Video Clip Video clip
Virtual signal timing and vehicle detection Return to Main Street to Accommodate NB Train Left Turn Phase Early Green for SB Train Main Street Green Cross Street Phase NB Train SB Train NB Advance Call SB Check-Out Call NB Check-In Call SB Check-In Call NB Check-Out Call SB Advance Call
Model MOE’s • Collected data on Measures of Effectiveness (MOE’s) • Travel time through test section • Delay through test section • Travel time for each movement (including cross streets and left turns) • Delay for each movement Queue length • Priority Strategies
Modeling Results • Both Systems are very complicated! • Results showed that VS-Plus was better for TSP, but Nextphase was better at reducing delay to vehicles overall. • However, level of TSP/vehicle delay could be adjusted for either software. • We initially selected Nextphase because we already had trained technicians in software.
Where are we now? • Unsatisfied with user interface for transit priority and program complexity of Nextphase • Reconsidering software options • VS-Plus • 2-ring software programs • Naztec • Sepac • City of Los Angeles • Econolite • Newly developed software
Lessons Learned • We have a vision, but getting there isn’t easy… • Modeling cannot capture complexity of programming • Must thoroughly learn the TPS software before selecting • Need to find balance between competing elements • Transit Priority • Pedestrians • Traffic Circulation • General Safety • Complexity of Programming