New traffic lights could save city money

LEDs require less energy, maintenance than bulbs

November 03, 2003|By Matt Whittaker | Matt Whittaker,SUN STAFF

The city's plan to overhaul Baltimore's traffic signal system won't make waiting at red lights any less aggravating, but it should save hundreds of thousands of dollars a year.

Aiming to cut energy and maintenance costs, city officials want to replace traffic lights that use standard incandescent bulbs with ones that use light-emitting diodes.

The longer-lasting and more efficient LED technology will be employed at all of the city's 1,300 traffic signals after the city selects a company to do the work.

"We're spending $800,000 on energy per year just to light our traffic signals," said Frederick Marc, chief of the Department of Transportation's engineering division, and "we replace bulbs constantly."

He said the current incandescent bulbs last for about 7,000 hours -- less than a year -- but the LEDs can last more than a decade.

Marc said the city will save on maintenance costs because bulbs won't have to be replaced as often.

Another money-saving feature of LEDs is that their brightness can be increased during the day and decreased at night, saving energy. Incandescent bulbs burn at a constant rate.

The conversion process started recently when the Department of Finance's Bureau of Purchases advertisedin newspapers and on the city Web site asking for information from companies that might be interested in replacing the signals.

Through the company responses, due by Dec. 10, the Department of Transportation hopes to learn more about LED technology and put together a proposal with specifications of what the city needs.

The city will then accept bids based on its proposal and choose a company to do the work. It will take the city about six months to assemble the proposal and three to four months to award the contract. The company that gets the contract will need about two years to replace all of the traffic lights.

Marc said that though the conversion will cost millions of dollars, the energy savings will be "substantial." They will take time to realize, though, because the vendor will be paid out of those savings in a process that may take five years.

"We are trying to change the traffic heads at no additional cost to the city," said Michael Krupnik, an electrical expert with the Bureau of Purchasing. "The energy [savings] will actually pay for the project."

Krupnik said LED traffic signals are more reliable than conventional ones because they emit light from many different dots, and do not burn out all at once. He added that LEDs use 85 percent less energy than incandescent bulbs.

The city's request for information also asks vendors to explore possibilities for solar-powered signals and signals that are compatible with video cameras.

The Department of Transportation would like to install video cameras at some intersections to monitor traffic conditions and would like the LED lights to be able to accommodate the cameras, Marc said.

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