Traffic Signals Improvements Project (IDEA Grant Project)

This project will implement adaptive traffic signal control along select corridors to improve operations and deploy an ATSPM (Automated Traffic Signal Performance Measures) system to improve monitoring and management capabilities. 

The primary objectives of the adaptive traffic signal system in this project are to accommodate the varying traffic patterns, provide smoother traffic flow along the main arterials within the project area, and accommodate future developments within and near the project area. 

The corridors for adaptive signal control are: 

- Union City Boulevard: From Kohoutek Way to Alvarado Boulevard (6 traffic signals)

- Decoto Road: From 7th Street to Clover Street (7 Traffic Signals)

The project will also install passive pedestrian detection at four (4) intersections to enhance pedestrian and bicycle safety. The intersections are:

-    Alvarado Boulevard and Dyer Street

-    Alvarado-Niles Road and Hop Ranch Road

-    Alvarado-Niles Road and Royal Ann Drive

-    Decoto Road and Meyers Drive

An adaptive traffic signal system is one in which some or all the signal timing parameters are modified in response to changes in the traffic conditions, in real time. The purpose of providing adaptive control in the project area is to overcome the limitations of the existing system to handle the varying traffic pattern introduced by the surrounding commercial and institutional facilities or by major traffic incidents on the nearby I-880 freeway and SR 238. This project will add adaptive capabilities to the functionality of the existing coordinated signal system.

The vision of the ASCT (Adaptive Signal Control Technologies) system is to provide an advanced traffic control system that responds to changing traffic conditions and reduces delay and corridor travel times, while balancing the needs of all roadway users.

The goals of the ASCT system are: 

  • Balance multimodal needs. 
  • Support vehicle, pedestrian, and transit traffic mobility and address safety concerns.
  • Provide measurable improvements in personal mobility.
  • Support regional systems. Two major corridors pass through the City, I-880, a freeway, and SR 238, a major arterial, which provide access north to Oakland and San Francisco and south to San Jose. Regional traffic uses these highways to reach other regional routes as well - the City is flanked by two major regional east-west highways, SR-92 and SR-84, which provide access across the Bay to cities such as San Mateo and Palo Alto. Routes such as Union City Boulevard and Decoto Road serve regional traffic but also serve as reliever routes when there are incidents on these freeways.
  • Support congestion and environmental policy objectives.
  • Safely and effectively recover from unexpected events, such as railroad preemptions, freeway incidents, high priority emergency vehicle preemptions, and low priority transit preemptions.
  • Enhance transit performance.
  • Enhance incident response time for first responders.

To support this vision and goals, the following objectives were identified:

  • Minimize adverse effects caused by preemption and unexpected events, such as: 
  • Freeway incidents which result in additional through traffic on City streets. The City’s objective is to more effectively flush traffic through during freeway incidents 
  • Recovery from rail preemption, including a situation in which both Amtrak trains and Union Pacific trains are approaching an area at the same time
  • Adjust operations to changing conditions: 
  • Enhance corridor operations during off-peak and weekend periods 
  • Balance service to both directions on the major street while minimizing delays to side streets to the extent possible 
  • Adaptive system to call special plan when volumes near schools trigger it (i.e. when school ends at 1:30 pm instead of 3:30 pm) 
  • More effectively serve special event traffic, such as soccer tournaments, and areas near large traffic generators, such as Costco, FedEx, hospitals 
  • Reduce delays on a corridor level and/or on an individual intersection level, depending on the operational goals.
  • Improve travel time reliability 
  • Enhance safety for vehicles, pedestrians, and transit 
  • Be compliant with the regional ITS architecture 
  • Reduce emissions through improvements in appropriate determinants such as vehicle stops and delays

The vision of the ATSPM system is to provide a cost-effective performance measurement system that ensures people can arrive at their destination safely and travel efficiently and reliably regardless of mode choice.

The goals of the ATSPM system are to: 

  • Provide safe operations—incorporate proactive operations and maintenance practices to reduce traffic congestion that results from poor and outdated signal timing 
  • Enable efficient and cost-effective maintenance— identify equipment failures more quickly and provide staff with the information to maintain signals in an excellent operating state 
  • Improve operations—actively monitor the signalized intersection performance so problems can be addressed before they become complaints 

        To support this vision and goals, the following objectives were identified: 

  • Continuously monitor the operational effectiveness and reliability of traffic signal coordination plans Continuously monitor the maintenance condition of detection devices 
  • Systematically identify traffic pattern shifts 
  • Assess signal phasing and splits for throughput optimization and travel delay reduction 
  • Verify complaints and troubleshoot operational issues 
  • Increase safety of intersection operation 

The project is anticipated for completion mid-2022.

This project is made possible by the Bay Area Air Quality Management District, the Metropolitan Transportation Commission (MTC) IDEA Grant and a grant by the Alameda County Transportation Commission (ACTC).


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