Traffic Signal Coordination Goals

The goal of coordination is to get the greatest number of vehicles through the system with the fewest stops in a comfortable manner. It would be ideal if every vehicle entering the system could proceed through the system without stopping. This is not possible, even in well-spaced, well-designed systems. Therefore, in traffic signal coordination, the busiest traffic movements are given precedence over the smaller traffic movements. If you are waiting for a green light to cross the "coordinated" street where there is heavy traffic on the main street and very light traffic on the side street, you will probably feel like you are waiting for a very long time.

Many of the traffic signals located within the City of Irvine's jurisdictional boundaries are not owned and operated by the City. The State of California owns and operates the traffic signals at every freeway ramp. With three freeways running through the middle of Irvine, you can see where the natural breaks will occur in every coordinated signal program. You can expect to stop at each of these locations.

In addition, Irvine continues to experience construction on many of the City's major arterial streets. As result of the construction, there is usually interruption to the traffic signal system resulting in a loss of traffic detection capability and communication to the City's Irvine Traffic Research and Control Center (ITRAC) with the surrounding signal system. Therefore, the affected traffic signals are placed on a fixed time operation, which is based on a typical traffic volume. This type of operation is not responsive to changing traffic volumes, and drivers will most likely find that they have to wait at these intersections when there is no cross traffic. Once construction is complete and communication is restored with the ITRAC Center, the City traffic engineers will evaluate the traffic patterns, develop new coordinated patterns and return the roadway to an actuated or on-line traffic signal system.

Some other challenges of coordinating Irvine's traffic signals include:

  • Communication interconnect cable and vehicle detection damaged by construction
  • Reduction of lanes during construction
  • Equipment or detection failure
  • Off-peak travel which is not coordinated or heavy traffic opposite the major flow of traffic
  • Heavy cross traffic (where two or more major arterials intersect)
  • Pedestrian or bicycle traffic
  • Intersection capacity overload
  • Wide intersections
  • Odd shaped City boundary lines

 

You can help by calling the number listed below and providing the specific concern or problem, and giving the location, travel direction and the time of day the concern or problem was observed