Study says nation's traffic lights are woefully inefficient and outdated

I hate traffic lights, and I'll bet you do, too. Read on...

http://www.usatoday.com/news/nation/...signals_x.htm#

Traffic lights get an F in efficiency

By Larry Copeland, USA TODAY


WASHINGTON — The nation's traffic lights are woefully inefficient and outdated, forcing frustrated commuters to sit in congestion, waste gasoline and pollute the air, a traffic engineering group said Wednesday.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

This issue has years worth of inertia working against it.

The excuse you always hear at the local level is that it costs way too much to computerize the lights. Officials will cite some absurd-sounding figure like $1M per signal, and state flatly that there is no way that they can fit something like that into their budget, unless the citizenry is willing to let those potholes sit for awhile.

Too bad we can't figure out some homeland security angle to get some money thrown at this issue. ;)

Slightly off-topic and from a couple years ago.

http://www.energy.ca.gov/releases/20...d_signals.html

California 'Green Lights' Energy Savings
With New Traffic Signals

SACRAMENTO - New, brighter, more energy efficient traffic lights are appearing throughout California, a result of efforts taken to prevent last year's electricity crisis. Because of the new signals, 80 different local agencies are saving money on their electric bills, California's electricity supply is a little more secure, and over 13,000 intersections Ñ nearly a third of the intersections in the State Ñ are safer than they were a year ago.

The California Energy Commission reports that, through its program offering loans and grants to local agencies, over 236,780 old incandescent red, green and amber traffic signals, along with pedestrian walk and don't-walk signals, have been replaced with new lamps that use light emitting diodes (LEDs). The new LED lights reduce the State's need for electricity by nearly 10 megawatts Ñ enough electricity to power nearly 10,000 typical California homes. That means the electricity saved by LED traffic signals alone could supply all the homes of a California town the size of Benicia, Folsom, Claremont or Imperial Beach.

Instead of a single incandescent light bulb, the new LED lights feature a number of smaller lights assembled in one unit. Together, the numerous pinpoints of light from an LED lamp are brighter than a comparable incandescent lamp, and as much as 80 percent more energy efficient. While traditional incandescent traffic lamps use between 69 and 150 watts each, LED lights use between 10 and 25 watts, depending on size, color and type. That reduced electricity demand should save the 80 public agencies participating in the Energy Commission's LED traffic signal replacement program an estimated $7.9 million every year on their electricity costs.

LEDs provide other cost benefits as well. When an incandescent traffic signal lamp fails, it burns out all at once, and incandescents typically need to be replaced every two years. The numerous pinpoints of light in an LED lamp, on the other hand, don't all burn out at the same time, and LED lamps can have a lifespan of up to ten years. Fewer burned out traffic signals means safer intersections, an important improvement in public safety. Agencies that have installed LEDs have discovered additional savings in traffic signal maintenance and lamp replacement costs because highway crews need to replace burned-out traffic signals less frequently. As an additional safety feature, brighter LED lights are more visible in foggy conditions.

To date, State grants and loans for the replacement program total nearly $22 million. Funds for the program were provided by Assembly Bill 970 and AB29X, landmark emergency legislation designed to cut electricity use in 2001; and the Energy Conservation Assistance Act and the Local Jurisdiction Account, two existing programs which authorize the Energy Commission to issue loans to local governments for installing energy-conserving equipment.

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Note to Editors: A list of cities, towns and local agencies that have benefited from the Energy Commission's LED replacement program is available below.