vta traffic light priority
The Future of VTA’s Transit Signal Priority
09/12/2023
priority signal event at VTA

The Intelligent Transportation Systems CA (ITS CA), in partnership with South Bay Transportation Officials Association and Association of Public Works Agency, recently held a luncheon at VTA headquarters where more than 50 transit professionals had an opportunity for networking and change-making in all arenas of smart transportation.

The event had three main presentations on the following emerging technologies:

  • Centralized transit signal priority system
  • Traffic signal controller cabinet
  • Use of connected and automated vehicles to harmonize speed on a congested freeway.

David Kobayashi,  Senior Transportation Engineer at VTA presented on VTA’s effort to plan and deploy a centralized transit signal priority system called Transit Reliability Improvement and Performance System (TRIPS) project.

Transit Signal Priority  is a set of traffic signal treatments to move a transit vehicle quicker through a signalized intersection.

priority signal event at vta

The goal is to provide priority within a traffic signal cycle without disrupting operations.

Types of traffic signal timing treatments:

Green Extend: Provides additional time when a transit vehicle arrives at the end of green phase.

Truncate Red:  Shortens green time for the side street when a transit vehicle arrives during a red phase.

The TRIPS project is seen as VTA’s future for the deployment of transit signal priority (TSP) throughout the County.

It differs from the past technologies that used infrastructural based components at the traffic signal and on our transit vehicles to being solely software driven.

The new approach uses the existing low latency communication for VTA’s Computer Aided Dispatch/Automated Vehicle Location to track our vehicles in real-time and to the local agencies’ traffic signals.

Coming this fall, VTA will be starting an effort to define critical functions of the centralized TSP system with a goal to procure the solution within a year from now, including defining where the solution is truly needed with key components to include public engagement to define priority routes for its deployment.

Traffic Signal Controller Cabinet

Darren Thai with the City of San Jose – Department of Transportation presented on a key for the traffic signal controller cabinet that is a physical key with a digital encryption function as an added security measure.

Before using the physical key, the digital function of the key must be authorized for use through an App or web interface. If the key is lost, the digital authorization can be revoked, and the traffic signal controller cabinet cannot be unlocked.

The reason for implementing this technology stems from a security audit by the Department of Homeland Security to control the access to vital infrastructure such as a traffic signal controller cabinet.

schoolarship to students

Freeway Traffic Solutions

Jonny Lee with Circles Consortium presented on a research project conducted by UC Berkeley and Vanderbilt University and two automobile manufacturers that implemented the use of connected and automated vehicles to harmonize speed on a congested freeway in Tennessee.

The goal of the research project was to reduce instabilities in traffic flow at freeway bottlenecks, using a small number of connected/automated vehicles as pilot vehicles to control speeds and improve flows through these bottlenecks. The preliminary data showed some improvement in flows. 

In addition, during the event it was announced a $5,000 scholarship will be awarded to two students pursuing transportation with a focus on the ITS area.

Who is ITSCA?

The Intelligent Transportation Society of California (ITSCA) is a professional organization to promote, educate, and to drive the implementation and deployment of transportation in California.

For more information about the organization, please visit https://www.itscalifornia.org/

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