TRANSPORTATION OPERATIONS | SIGNALS - SIGNAL CENTRAL

San Jose's Traffic Signal Management Program (TSMP)Unit provides the community with an efficiently managed, state-of-the-art traffic signal system. The TSMP Unit, part of the Department of Transportation, uses innovative and advanced traffic control and monitoring technologies. On a regional level, the TSMP Unit contributes to an effective transportation system by linking its efforts to other South Bay cities through the Silicon Valley Smart Corridor project.

The Challenge... As the City of San Jose continues to grow, traffic has challenged the City's ability to add to the existing roadway system. The congestion and delay caused by traffic demand result in increased air pollution, additional fuel consumption, and a waste of motorists' valuable time. Motorists and residents both benefit from the TSMP. Quicker commute and reduced auto emissions help to preserve the quality of life in San Jose.

The Solution... The TSMP synchronizes traffic signals to minimize delay to motorists traveling through the City, and monitors the operation of traffic signal equipment to improve maintenance and repair response times. Cameras and detector loops provide data necessary to make appropriate timing changes.

The System... The focal point of the TSMP is the traffic operation center, SIGNAL CENTRAL, located in the offices of the City's Department of Transportation in downtown San Jose. Currently, over 500 of the city's 800 traffic signals are connected to Signal Central. The traffic signal controllers are connected to the system through a combination of City-owned cable, leased telephone lines, microwave communication, and spread spectrum technology.

Monitoring the operations of the traffic signals provides vehicle count data from on-street detectors and instantaneous notification of equipment malfunctions. The vehicle count data is used by the central system to select the most efficient traffic synchronization plan for current traffic conditions and to develop improved timing strategies. The vehicle count data is also used in many other transportation planning activities. In addition to providing improved service for normal recurring traffic flows, the TSMP is also designed to alleviate the impacts of incidents, accidents, and special events, which combined, have been estimated to cause up to 40 percent of the daily congestion in urban areas. Special timing plans are being developed to address the closure of major routes due to accidents or incidents. Event operation plans are specifically designed to address special events in the downtown, Spartan Stadium complex and elsewhere in the city. The TSMP staff relays important data back to travelers by using variable message signs and highway advisory radio.