Traffic lights get an F in efficiency

Top Stories - USATODAY.com
USA TODAY
Traffic lights get an F in efficiency

Thu Apr 21, 6:41 AM ET

By Larry Copeland, USA TODAY

The nation's traffic lights are woefully inefficient and outdated, forcing frustrated commuters to sit in congestion, waste gasoline and pollute the air, a traffic engineering group said Wednesday.


Two-thirds of 378 traffic agencies in 49 states don't actively monitor traffic lights, or they simply respond to problems as they occur, the Washington-based Institute of Transportation Engineers reported.

"While traffic signals do turn green, yellow and red, they are not operating as efficiently as they should," says Shelley Row, the group's associate executive director. "The traffic changes during the day. (Agencies) need to be able to time the signals differently at different points during the day. "

A study by a Maryland researcher last year found that 35% of the nation's traffic agencies had not retimed their traffic signals in 10 years. That means they haven't responded to business and residential growth that affects traffic patterns, says Philip Tarnoff, director of the Center for Advanced Transportation Technology at the University of Maryland.

"The costs (of traffic signal management) compared to building a highway are trivial," he says. "The question is why isn't it being done more often?"

The stakes are high. Ideal management of traffic lights would cut delays by 15%-20%, reduce travel time by up to 25%, cut emissions by up to 22% and reduce gas consumption by up to 10%, according to the transportation engineers, who conducted their survey with the Federal Highway Administration and other groups. The survey estimates that improving the nation's traffic signal operations would cost about $965 million a year.

Two cities that get stellar marks in the study for managing traffic lights are Bellevue, Wash., and Springfield, Mo.

Bellevue (population 120,000) connects 90% of 172 traffic lights to a centralized network that includes 20 cameras, says traffic engineering manager Mark Poch. "That allows us to make adjustments for events that are happening right now," he says.

An example: About 9:30 a.m. Wednesday, construction on northwest Fourth Street forced the closure of one westbound lane on the six-lane road. Engineers adjusted the timing of traffic lights on Fourth Street to take time away from drivers on intersecting streets to compensate for the closed lane, Poch says.

In Springfield, engineers use cameras to monitor 28 miles of roads and 100 traffic lights and alert drivers to problems, says Earl Newman, assistant public works director. Voters in the city of 156,000 have approved eight local sales tax initiatives to reduce congestion, which ranks as the public's top concern, he says.

"It's higher than crime," he says. "We don't have the congestion of a major city, and the citizens don't want it to become like that."