The proliferation of LED lights in traffic light fixtures around the country are saving municipalities millions of dollars, but with a heavy dose of winter weather this month the same municipalities are learning to deal with the unexpected problem of snow-covered traffic lights. Because the LED’s generate less heat, they fail to melt off the snow that is covering the red, yellow, and green lights.

An AP report looks at problems in the Badger state:

Wisconsin, which has put LED bulbs at hundreds of intersections, saves about $750,000 per year in energy costs, said Dave Vieth of the state Transportation Department. LEDs installed seven years ago are still burning, while most incandescent bulbs have to be replaced every 12 to 18 months, he said.

“With LEDs we have energy savings in excess of 80 percent, and we don’t have to have crews replacing them as often,” Vieth said. “So it’s clear the overall savings are pretty significant.”

What solutions exist to deal with the LED problem?

Authorities in several states are testing possible solutions, including installing weather shields, adding heating elements like those used in airport runway lights, or coating the lights with water-repellent substances.

The Chicago Tribune weighs the costs and benefits of LED lights and the snow problem:

LEDs “are much more visible to the motorist so they have more time to see the traffic signal and react,” Tobias said. “Not only are we addressing energy efficiency, we’re also improving safety at intersections.”

In Chicago’s suburbs, engineers say snow can cover LED traffic signals, but only under certain conditions — wet, driving snow and freezing temperatures — and rarely every signal at an intersection.

They say the problem is easily remedied by maintenance crews using brooms and occurs so infrequently — once or twice a winter — that it does not outweigh the benefits of energy efficiency.

Another article interviews Green Bay traffic engineer Dave Hansen:

Hansen is looking to test several new products to prevent the snow from sticking. One is a bubble-shaped plastic shield placed over the light, angled to make the snow fall off.

Hansen is also researching a cover with a vent on top that would allow wind to blow through, blowing the snow out of the traffic light.

Photo Credit

Tags: LED, Snow, Traffic Lights

This entry was posted on Friday, January 15th, 2010 at 3:38 PM and is filed under Accidents, Civil Engineering, Safety, Traffic. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.