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

New Central Subway to Chinatown

Funded by Federal Match

Currently in Conceptual Engineering

4 Underground Stations

General Project Features – Phase 2

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

Existing

20053rd 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

Transit Ridership & Travel Times

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

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)

• 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

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

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

CesarCesar ChavezChavez

EvansEvans

CargoCargo

Video Clip

Video clip

Early Green for SB Train

NB Train

NB Check-Out Call

SB Train

SB Check-In Call

SB Check-Out CallNB Advance Call

NB Check-In Call

SB Advance Call

Virtual signal timing and vehicle detection

Return to Main Street to Accommodate NB TrainLeft Turn Phase

Main Street Green Cross Street Phase

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 – 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

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