T3 Webinar Presentation

Is Your Region Ready for BRT? A Los Angeles/New York ITS Peer-to-Peer Exchange (April 16, 2008)

Transit Priority Systems (TPS)

Presenter:   Chun Wong
Presenter's Org:   City of Los Angeles, Department of Transportation

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Slide 1: Transit Priority Systems (TPS)

T3 Webinar on Bus Rapid Transit Webinar
April 16, 2008
Chun Wong, P.E.
City of Los Angeles, Department of Transportation

Slide 2: "Smart" Transit Priority System (TPS)

[Image of a bus, a traffic signal, and a light bulb. The slide indicates that Transit Priority System is a combination of equipment (bus), hardware (signal) and ingenuity (light bulb). ]

Slide 3: Project Overview

  • LADOT partnered with LA Metro in National Bus Rapid Transit (BRT) Demonstration Program since 2000
    • Wilshire/Whittier & Ventura
  • Strong Mayor commitment to improve LA transit services
  • Improve bus run time performance
  • Improve ridership
  • Successfully implemented 18 Metro Rapid bus corridors and the Metro Orange Line
  • Reduced 25% total travel time

[Images: Computers and desks in a Transportation Management Center. Image of front of bus in traffic.]

Slide 4: Project Objectives

  • Provide schedule adherence
  • Operate within existing street infrastructure
  • Minimize cross street impact
  • Provide bus arrival information
  • Improve transit experience

Slide 5: Existing Infrastructure

  • City’s central Urban Traffic Control System (UTCS) - ATSAC
  • One-second communication poll
  • Type 2070 traffic controllers

[Image of man sitting at a terminal in a Transportation Management Center.]

Slide 6: LA Transit Priority Systems Solution

[Images of devices used LA’s transit priority signal system. Includes a transponder affixed to a bus bumper, a loop detectors embedded in a road, a 2070 controller, and communications center. These images surround a center image of an intersection equipped for transit priority. The image shows a bus headed toward the intersection, transmitting signals to the traffic signal controller.]

Slide 7: TPS Components

  • Inductive loop/transponder detection
    • Low frequency hockey puck liked transponder
    • Curb-to-curb elongated loop sensor
  • Model 2070 traffic controller
  • Check-in / Check-out detection
  • ATSAC communication network

Slide 8: Transit Priority Manager

  • Centralized System
    • PC based server
    • Real-Time
    • Track vehicle positions
    • Determine late/early
    • Issue signal priority
    • Calculate bus arrival
    • Publish bus data
    • Retrieve run time data
    • Implement TOD headway plan
  • Non Real-Time
    • Archive to database for trip analysis

[Image: Screen host of Transit Priority Manager system. ]

Slide 9: Preemption ≠ Signal Priority

  • Preemption
    • Interrupt signal operations
    • R x R crossings
    • Emergency vehicles
  • Signal Priority
    • Modify signal operations
    • Maintain coordination
    • Borrowed time (10% of cycle length)

Slide 10: Priority Treatments

  • Early green
    • Vehicle detection required
    • Red truncation
  • Green extension
    • Vehicle detection required
    • Extend green phase
    • Most efficient priority
  • Call Phase
    • Left/Right turns

Slide 11: Headway Algorithm

  • In-house developed
  • High bus frequency service – low headway
  • Leverages Hot List / Run List
  • Time-point propagation (TPP)
  • Load-balanced

Slide 12: LADOT Transit Priority Systems (TPS)

[Images of a Metro Rapid Buss, Metro Orange Line bus, street-embedded bus sensor, transponder, iTRAQ website, graphics display, passenger information system, a traffic signal, and a mobile internet passenger system. All of these images surround a center image, which is a screen shot of the TPS computer-based system. The slide shows that information is exchanged between the central system and devices I the field.]

Slide 13: Multi-jurisdictional TPS

  • Countywide BSP (Bus Signal Priority) Program
  • WiFi 802.11b
  • On-board GPS tracking
  • Distributed system

[Image of intersection equipped for transit priority signal operations. Thumbnail image of map and location of LADOT Transit Priority Signals.]

Slide 14: BI-Tran 2033 & L.A. TPS

[Image of BI-TRAN 2033 & L.A. TPS schematic.]

Slide 15: TPS Communication Option

[Image of TPS Communications Options schematic.]

Slide 16: TPS Map Client Software

[Image of TPS map client software. Shows dialogue boxes displaying Bus Arrival Times, Traffic Controller Status, and Bus Runtime Info.]

Slide 17: Passenger Information System

  • Real-time data
  • Integrated with TPM
  • ETA Count down
  • Lead bus’ travel time
  • LED Displays
  • Communication
    • CDPD wireless by AT&T
      • Obsolete
      • Coverage
    • Hard-wired FSK (Frequency Shift Keying)
      • Traffic control device

[Images of LED signs displaying passenger information.]

Slide 18: Mobile Internet Passenger Systems (MIPS)

[Image of metro rapid website and a person holding a cell phone, indicating the availability of the Mobile Internet Passenger System (MIPS).]

Slide 19: TPS Real-Time Data Collection

[Images of devices in transit priority system real-time data collection. Includes a traffic signal, transit priority manager, real-time graphical displays, real-time data logging, and the Transit Report and Query (iTRAQ) web server.]

Slide 20: i Transit Report And Query

  • Leverages existing TPS architecture
    • Field equipment (Loop/Transponder AVL, 2070 Controller, etc.)
  • Automates 24 x 7 transit trip data collection
    • Weekdays; weekends; holidays; rainy days, etc.
  • Uses commercially standardized Relational Database system (RDBMS)
    • Oracle Database System
  • Publishes through Web Server
    • Simplify RDBMS data access
      • Client workstations request no complicated ODBC and/or RDMBS setup
    • In-house developed web application
    • Microsoft IIS 6.0
  • Performance Measure Tool

Slide 21: iTRAQ Web Interfaces

[Image of screen prints of iTRAQ computer interfaces.]

Slide 22: Lesson Learned

  • Transit and DOT partnership
  • Existing infrastructure
  • Budget constraint
  • Must / desired features
  • Operation / Maintenance cost

Slide 23: The End

Questions & Comments

Send questions to:
Email: chun.wong@lacity.org

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