Tucson Region Street Signs Sparkle in Solar Pilot Program
By Andrea Kelly
Arizona Daily Star
July.21.2008

One of the city's pilot solar-powered signs is on southbound Silverbell Road just north of Congress Street.

A few street signs in Tucson now boast a popular ecological tag: solar powered.

Two signs warning drivers of a sharp turn at West Congress Street and North Silverbell Road sport flashing yellow light-emitting diode lights to make the caution signs extra visible.

Tucson International Airport uses a stop sign and a pedestrian crossing sign adorned with flashing LED lights to grab drivers' attention in busy areas. The signs all have solar panels nearby, and they flash all day and night.

The Tucson Department of Transportation is testing the lights at Congress and Silverbell to see if they stand up to our heat and remain visible during the bright, sunny days, said Richard Nassi, city traffic engineering administrator.

The Tucson Airport Authority installed its two test signs signs in March at high-traffic areas to see if they better regulate traffic, said Daniel Morelos, operations director for the authority.

They've worked well enough that the authority is considering buying them, and possibly a few others.

The airport signs are a pedestrian crossing sign on the lower level, where passengers are picked up, and a stop sign just after the pay booth for the parking lot, where traffic should stop before merging onto South Tucson Boulevard.

"They've just been so successful in what we're trying to accomplish, which is pedestrian safety," Morelos said. These and the city's caution signs are the newest solar signs to shine on city streets. The city already has solar-powered traffic signals at two fire stations, Nassi said. These signs were supplied for free for Tucson to test them, and because they run on solar power, they don't cost the city anything, he said.

"The summertime is the toughest time for light-emitting diodes. Heat is one of the most destructive things for the diodes," Nassi said. "We're putting them through the thermal test right now."

The city will monitor how well drivers do at the Congress and Silverbell corner with the signs, but because it hasn't been a problem area in the past, it's not likely to be a problem now, he said. The city's six-month test began a little more than a week ago.

"We're not only testing them during the heat, but whether they're visible during the Arizona daylight, because it's pretty bright out there," Nassi said