Light-Emitting Diode, LED, traffic signals are slowly being phased in across the state. The old signals, which use 150-watt incandescent light bulbs, are on the way out.
The LEDs, made up of many small lights on a grid, are brighter and save energy.
"It's about one-eighth to one-tenth the energy consumption of an incandescent bulb, and we're also increasing the life of the display so that our signal technicians don't have to go out and be in the street to replace the bulbs every one to two years," says Milton Dean, a DOT signal engineer.
The lights, which last about five years, also cost more.A red LED light costs $75 compared to about $2 for the old bulbs.
Engineers say the new lights will pay for themselves in five years, with savings on energy and maintenance.
The new traffic lights can be found at several Wake County intersections: Highway 64 at Maplewood Drive, Highway 64 at Smithfield Road, Six Forks Road at Lassiter Mill Road and Six Forks Road at Forum Drive.
The DOT plans to convert every traffic light statewide to the new LEDs, and says it can get to all of North Carolina's 8,000 signals in five years.