3rd Street Light Rail

1
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
2
Outline

• Project Background
• Existing Conditions
• General Project features
• Timeline and Goals
• Transit Priority
• Software selection process
• Vissim Modeling
• Results
• Lessons Learned

3
Existing Conditions

• 5.4 mile corridor
• 35 signalized intersections
• 3 traffic lanes in each direction with parking
• Serviced by MUNIs 15 Bus line
• 7 to 15 minute headways
• Current ridership 25,000

4
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

5
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

6
Project Goals

• Improve Transit Service along Corridor
• Reduce travel time and delay
• Increase ridership
• Connect Southeast SF to Downtown
• Transit Oriented Development
• Economic Revitalization

7
Transit Ridership Travel Times
Existing 2005 3rd Street LR 2015 3rd St. LR Central Subway
Daily Ridership 25,000 71,000 95,000
Travel time to 3rd/Market from Visitation Valley (Arleta/Bayshore) Bayview Core (Third/Palou) Mission Bay 36 min 26 min (N/A) 31 min 23 min 14 min 27 min 19 min 10 min
8
Construction Schedule
Segment B Mission Bay February 2004
Segment C Central Waterfront March 2005
Segment D Bayview/Hunters Point February 2005
Segment E Bayview South US101 Overpass February 2005
Segment F Visitacion Valley May 2004
Segment J Platform Finishes Traffic Signal Priority System/VETAG Controllers May 2005
9
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

10
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

11
Transit Priority Strategies

• Skip Phases
• Extend Phases
• Shorten Side Street Phases
• Lead/Lag (phase rotation)
• Early Green
• Get Back in Step within 1 Cycle

12
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

13
Software Wish List

• General Features
• Pedestrian Features
• Transit Priority
• General Preemption
• Cable Car Preemption
• Coordination
• Communications
• (full list available upon request)

14
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

15
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.

16
VISSIM Modeling Process
Cesar Chavez

• 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
17
Video Clip

• Video clip

18
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
19
Model MOEs

• Collected data on Measures of Effectiveness
  (MOEs)
• 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

20
Modeling Results Travel Time Through Test
Section
Movement Fixed time optimized for Cars Fixed time optimized for Trains Nextphase VS-Plus
NB Cars 210 237 172 165
NB Trains 247 243 211 155
SB Cars 319 330 181 155
SB Trains 350 324 197 157
21
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.

22
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

23
Lessons Learned

• We have a vision, but getting there isnt 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