Growing numbers of cities and towns are turning to solar-powered road warning and school safety signs to inform the public and save money and energy.
In the past year, cities including Baton Rouge, Branson and Kansas City, Mo., and Lyndhurst, Wayne and Ringwood, N.J., have adopted the technology, officials in those municipalities say.
Rick Bergholz, owner of TAPCO, a Wisconsin-based company that manufactures and sells the environmentally friendly traffic controls, says solar-powered light "sales have been exploding."
"They've been around since their inception 10 years ago, but it took years to perfect the product and to get approval," Bergholz says.
TAPCO's website lists Fort Worth, Tucson and Richfield Township in Ohio among other solar signal clients.
In Baton Rouge, flashing yellow lights at school zones went "green" before the start of the current school year, says Ingolf Partenheimer, the city-parish's chief traffic engineer.
"We are putting out 90 of them," Partenheimer says, adding that they can electronically change the signals instead of having to change them manually. "If a school has early dismissal, we can change the signals school-by-school or globally."
Branson installed solar signs at a cost of about $1,000 each a few months ago at two intersections that had seen numerous accidents, says Keith Francis, the city's assistant director of public works.
"We had had numerous accidents at these locations, and it was kind of a dark area and didn't have a lot of street lighting, so we decided to put these up to get people's attention," Francis says. "Flashing lights automatically get people's attention and make them slow down."
"The solar portion cuts down on costs," he says. "The solar panels (batteries) will run for 11 days without being charged."
Shreveport, La., was among the early users, installing solar-powered lights five years ago, city traffic engineer Michael Erlund says. "We went with solar lights because electricity costs us money constantly," he says.
A solar-powered flashing stop sign was installed at a three-way stop in Hammond, La., in Tangipohoa Parish in early September, according to Gordon Burgess, Tangipahoa Parish president. It is one of 10 that will be installed on parish roads, he says.
In deciding where to place the signs, Burgess says, officials looked at several dangerous intersections.
"We have a lot of intersections, some with four-way stops, so we looked at where they've had accidents, and with our volume of traffic, we more or less prioritized the ones with the high traffic count," he says.
(Oscar Fann adds:
These solar powered signs have great potential, especially in the southern US.
However, in areas farther north, especially in the northern US, one BIG problem has emerged.
During the winter, the low sun angle reduces significantly the sun's strength. Combine this reduced solar power with the very real possibility of several cloudy days can result in malfunctioning solar powered signals. This happened last winter with traffic signals in areas near the western Great Lakes. Obviously, in certain situations, a backup power source should be available).