Investment Opportunities for Managing Transportation Performance: Background Information on Candidate ITS Technologies Background Information on Candidate ITS Technologies

Traffic signal system retiming and optimization ranks as one of the most cost-effective urban transportation improvement actions, increasing mobility, reducing fuel consumption, and improving environmental quality. The extent of benefits realized from traffic signal retiming depends on various factors including the quality of existing timing plans, street network configuration, and traffic patterns. For example, the Traffic Light Synchronization Program in Texas reduced delay by 24.6 percent, lowered travel time by 14 percent, and demonstrated a benefit-to-cost ration of 62:1. Signal retiming projects in several U.S. and Canadian cities have been shown to reduce fuel consumption by 2 to 9 percent and emissions by 1 to 6 percent. For optimal performance, traffic signal timing plans need to be updated at least every three to five years, and possibly more frequently depending on growth and changes in traffic patterns. The cost of retiming a signal is approximately $3,000. Based on the estimated 272,000 traffic signals in the United States and assuming that a fourth of these signals are retimed every year, the annual costs of signal retiming is roughly $200 million.