Every morning on your way to work, you pass through the same series of intersections. And, every morning you are stopped by a red traffic signal for no apparent reason; where you sit in a very long line of cars. The green signals never seem to be long enough, and once you make it through the intersection you are soon stopped by another red traffic signal. It is a tremendous source of irritation! The signals change colors but traffic never seems to move efficiently. You may be the victim of poor traffic signal timing and this scenario is repeated daily all around the country.
Updating traffic signal timing is a cost effective way to improve the flow of traffic on arterials and is one of the most basic strategies to help mitigate congestion. Of the estimated 330,000 traffic signals in the United States, and as many as 75 percent could be made to operate more efficiently by adjusting their timing plans, coordinating adjacent signals, or updating equipment. In fact, optimizing signal timing is considered a low-cost approach to reducing congestion, estimated at $2,500 to $3,100 per intersection to update. Optimizing traffic signal timing can produce benefit to cost ratios as high as 40 to 1. Those benefits include:
An image showing vehicles traveling through multiple traffic signals along a busy roadway.
It is estimated that poor traffic signal accounts for 5 percent of all supply-side traffic delay on major roadways. The U.S. DOT is working with the State and local transportation agencies to improve the management, operation and maintenance of traffic signal systems. The FHWA sponsored The National Traffic Signal Report Card which has confirmed the need for greater attention and investment in traffic signal operations. Improving traffic signal operations pays great dividends and is one of the most cost effective means of reducing congestion. One effective strategy to improving traffic signal operations is regionalizing traffic signal operations; meaning multiple agencies collaborate to leverage their signal timing expertise and resources to provide more consistent and efficient operations both within and across jurisdictional boundaries.