Cities’ Bright Idea: Give Traffic Signals a Change for Better

The reds and greens of traffic signals may seem brighter these days, but local cities aren’t playing a seasonal trick on you. Some stoplights are more radiant, and they won’t be dimmed once the holidays are over.

In recent years, cities throughout California have been replacing energy-draining incandescent bulbs in traffic signals with a longer-lasting light technology called LED that uses 90% less electricity.

Power shortages and soaring rates are spurring some cities to apply for state grants to help them change thousands more lights in coming years.

Though most drivers probably won’t notice the difference, on close inspection the LEDs, or light-emitting diodes, give traffic signals a pinpoint look, with rows and rows of small dots instead of a soft glow of the older bulbs.

The bulbs are consistently bright, their hue is darker and when LEDs are shut off there is no afterglow.

In contrast, incandescent lights are brightest at the center, fading toward the edges.

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Red LEDs, commonly seen as the small lights on stereo receivers, VCRs and the “power” indicator on many computers, have been around for decades. Only recently was the technology available for green and amber.

Because LEDs use only 10% as much electricity as incandescent lights, total annual savings would be $95 million if all 4 million traffic signals in the state were fitted with LED bulbs, according to the California Energy Commission.

In Laguna Niguel, officials expect to save 80% in energy and maintenance costs by converting to LED, traffic engineer Dave Rogers said.

The city changed about 15 lenses a few years ago and plans to change hundreds more by June 1, the deadline for a rebate program by San Diego Gas & Electric Co., which serves the city.

San Juan Capistrano converted almost all of its 260 stoplights through an SDG&E; rebate program offered two years ago.

An incandescent traffic signal bulb uses about 150 watts of electricity, while an LED uses about 18 watts, said Alan Oswald, senior traffic engineer for San Juan Capistrano.

“That’s a lot of energy savings,” he said. “It adds up when you consider all those 150-watt bulbs shining in different directions all over the city.”

The city of Ventura estimates it has saved 30%, or $4,000 a month, since installing more than 1,000 red LED bulbs in mid-1999, said Mark Watkins, the city’s public works manager.

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Rebates from Southern California Edison has helped Garden Grove and Seal Beach pay for their switch to LED signals. Anaheim, which operates its own electric utility, got funding from the California Energy Commission to replace its 254 red signals with LED.

A $305,000 grant will help pay for replacement of the green lights next year, said Taher Jalai, principal traffic engineer.

The one hitch is that LEDs are more costly: $100 to $125, compared with $1 for a standard incandescent bulb.

But traffic officials say the difference in life span offsets the higher price.

Standard bulbs last a year or two, while LEDs last from seven to 10 years. The cost of labor to replace the bulbs also goes down dramatically, transportation officials said.

The state energy commission has set aside $10 million in grants for cities to install LED lights. About $7.7 million has been distributed so far on a first-come, first-served basis, said Rob Schlichting, a commission spokesman.

“You never think of traffic signals having a cost, but they do,” he said. “If we can have brighter lights that won’t burn out as often and cost less, this is a situation where I don’t see any drawbacks.”