Howard County has completed the installation of backup power systems at all county-maintained traffic signals, public works officials announced last week.
Each battery-powered system will supply up to 10 hours of electricity, if there are power failures at any of 84 intersections, about half the traffic signals in the county. The systems cost about $4,000 for each intersection, said Diane Schwarzman, acting chief for traffic engineering for the Department of Public Works' Bureau of Highways.
"The group that benefits the most, I think, is the traveling public," Schwarzman said. "At certain times of the day at certain locations, it's very difficult, if you're on a side road, to get out onto the main road, especially if you want to make a left turn."
The initiative comes after a January 2006 accident that left two teenagers dead in Columbia when a tractor-trailer hit the car they were in at an intersection with a nonfunctioning signal. No officer was present at the time of the accident to direct traffic.
The county is working with the State Highway Administration, which maintains the other traffic lights in the county, to install systems at 20 of the remaining intersections. Seven of those have been activated, according to the county.
The month after the 2006 accident at Route 175 and Interstate 95, county police implemented a policy requiring officers to stay at nonfunctioning traffic lights until they are fixed or a temporary device is placed at the scene. The new backup systems also eliminate the need for officers to stand in the middle of busy intersections.
The traffic signals in the county can operate on batteries because they use LEDs, which use much less energy than traditional bulbs and last several years longer, Schwarzman said.
The county has reduced its traffic-signal energy consumption by about 67 percent since installing LEDs, she said.
tyeesha.dixon@baltsun.com