The LED traffic lights Wichita has installed at more than 90 percent of the city's intersections are far more efficient than the incandescent bulbs that used to burn red, yellow and green.
That saves money and energy for most of the year.
But when Wichita gets its two to three major snowstorms each year, burning less energy can be problematic.
That's because the LED lights don't generate enough heat to melt snow and ice.
It's not a problem at most intersections in Wichita even when there are heavy snows, said Joe Pajor, assistant director of public works.
But for a few intersections that have louvers — the shades that make it difficult to see what color the light is until you get close — snow buildup can be a problem, he said.
Those are typically only in places with two stoplights placed close to each other — such as under Kellogg.
Even when snow builds up, it typically doesn't totally block the light, and no accidents have been attributed to snow-covered traffic lights, public works officials said.
"We haven't had a problem except for rare occasions," Pajor said. "And we're in the process of fixing that."
The problem has been noted in several snowy states.
Earlier this month, the Associated Press reported that snow-covered lights have been blamed for "dozens of accidents and at least one death."
Some cities simply send trucks around with workers who clear the lights off with brushes or pressurized air.
Pajor said Wichita is considering different lens designs that are less likely to allow snow to accumulate.
Wichita usually sees one to three snowstorms that can lead to the type of accumulations needed to block stoplights, said Brad Ketcham, a meteorologist with the National Weather Service in Wichita.
"The thing that's nice here in Wichita is when we get snows like that it doesn't stay around long," he said.
Wichita began installing LED lights at intersections in 2001. Now 92 percent — or about 369 intersections — are controlled by LED signals.
Wichita examined energy usage on a signal at Rock Road and Rock Hill, near Bradley Fair. Its lights, computers and fans used $119.74 a month in energy when it had incandescent bulbs. With LEDs, it uses only $33.60 a month, Pajor said.
From another vantage point, the LEDs are safer — even if they do occasionally become blanketed in snow.
When incandescent bulbs burn out, they burn out completely. LEDs almost always fail one cell at a time — so they slowly get less visible.