Fortunately, those of us in Dallas don’t have to worry much about this problem reported by the Associated Press. Apparently in some northern cities drivers have discovered that new energy-efficient traffic lights with LED bulbs don’t burn hot enough to melt snow that accumulates around them. As a result, the lights become obscured, drivers can’t tell if they have a red or green light, and the potential for traffic accidents increases greatly. Here are excerpts from the story:
Many communities have switched to LED bulbs in their traffic lights because they use 90 percent less energy than the old incandescent variety, last far longer and save money. Their great advantage is also their drawback: They do not waste energy by producing heat.
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.
Short of some kind of technological fix, “as far as I’m aware, all that can be done is to have crews clean off the snow by hand,” said Green Bay, Wis., police Lt. Jim Runge. “It’s a bit labor-intensive.”
In St. Paul, Minn., for example, city crews use air compressors to blow snow and ice off blocked lights.
Not every storm causes snow to stick to the lights, but when the wind is right and the snow is wet, drivers should beware, said Gary Fox, a traffic engineer for the city of Des Moines, Iowa.
Exactly how much a technological fix will cost is unclear, but it will surely cut into the savings and the energy efficiency many cities are enjoying.
In Minnesota, where authorities have upgraded hundreds of traffic lights to LEDs, the Transportation Department occasionally gets reports of an obstructed light. But by the time a highway crew arrives, the wind has often knocked out the snow and ice, said traffic systems specialist Jerry Kotzenmacher. Minnesota is experimenting with weather shields.
One reason there have been so few deaths is that drivers know they should treat a traffic signal with obstructed lights as a stop sign, traffic experts say.
“It’s the same as if the power is out,” said Dave Hansen, a traffic engineer with the Green Bay Department of Public Works. “If there’s any question, you err on the side of caution.”
