Signals offer maximum control at intersections. They relay messages of both what to do and what not to do. The primary function of any traffic signal is to assign right-of-way to conflicting movements of traffic at an intersection. This is done by permitting conflicting streams of traffic to share the same intersection by means of time separation. By alternately assigning right of way to various traffic movements, signals provide for the orderly movement of conflicting flows.
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.
The City has established a traffic management facility called Irvine Traffic Research and Control Center (ITRAC) to monitor, manage, and research traffic circulation throughout the City.
ITRAC allows the City's traffic engineers to monitor on-line traffic conditions from City Hall and make appropriate adjustments to signal timing. Using advanced detection technologies, such as CCTV cameras and video image detection systems, the City's traffic engineers can obtain real-time traffic flow, counts, speed, and delays.
The quality of flow along a street is a function of the following:
Spacing of intersections along the street
Prevailing speed of traffic on the street
Traffic signal cycle length
Operation of the traffic signal equipment
Many drivers ask why they have to wait so long for a signal to change. Many of these drivers are waiting to enter a major arterial street from a side street. This is even more frustrating when no traffic can be seen on the arterial.
Scholarships for City Classes
The City of Irvine offers a scholarship program to help low-income Irvine residents participate in programs offered through the Community Services Department at a reduced rate. The program has limited funds available. Scholarships are granted on a first-come basis after applications are reviewed and approved. The program may be closed to new applications when funds run low.
Applications are available online at the link below.
To report a concern related to traffic signals, please call our Irvine Traffic Research and Control Center (ITRAC) at 949-724-7324.
Each year, the City receives many inquiries concerning the operation and installation of traffic signals within the City. The public's understanding of the function of traffic signals can improve driving habits by reducing speeding and associated traffic accidents. The more drivers know about the operation of traffic signals the less they will be frustrated when waiting for a signal to change.
FOR Families provides free information and short-term support to individuals, couples, and families living in Irvine who need assistance identifying and accessing needed services and resources. Since the late 1980s, our focus has been on supporting the well-being of our community members.
View more information here on what to expect when contacting FOR Families.
The City of Irvine is involved in a number of Intelligent Transportation System (ITS) activities in cooperation with the Federal Highway Administration, State of California Department of Transportation (Caltrans) and leading research organizations such as the University of California Transportation Studies at UC, Irvine.
The City of Irvine is a partner to the California Research Program with Caltrans and UC, Irvine that is designed to demonstrate the capabilities of real-time interconnectivity and data sharing between organizations.
Traffic Signal Synchronization is a traffic engineering technique of matching the green light times for a series of intersections to enable the maximum number of vehicles to pass through, thereby reducing stops and delays experienced by motorists. Synchronizing traffic signals ensures a better flow of traffic and minimizes gas consumption and pollutant emissions.
Traffic signals assign the right-of-way to various traffic movements for different time intervals depending on average traffic flow levels. Pre-timed signals have pre-set intervals for different times of the day including the morning, noon and evening peak travel periods. The City has a few fixed-time signals, primarily in construction areas.