Question: The city of Lakewood recently installed some new overhead traffic lights.
On the backside of a traffic light facing oncoming traffic, there is a small, intense blue light that comes on when the light changes to red (as I recall, could be when it changes to green).
Do you know what this blue light is for? — Jim Curley, Lakewood
Answer: The blue lights — sometimes called “rat lights” or “tattletale lights” — are there to help police catch red-light runners. They turn on simultaneously with the red light. That way, cops who aren’t in a position to see the red light can tell when a driver has entered the intersection after the light turns.
Brent Champaco, communications manager for the city of Lakewood, said the city installed the lights at two intersections at the request of the Police Department. You’ll see them at Gravelly Lake Drive and 100th Street and at Custer Road and John Dower Road.
The city of Tacoma doesn’t have any of the lights, according to city traffic engineer Josh Diekmann.
Champaco didn’t have any statistics on what the blue lights have done for enforcement in Lakewood, but the Federal Highway Administration says they work well and are less controversial than cameras.
A Department of Transportation study in Florida, where the lights are installed at more than 500 intersections across the state, credited them for reducing the annual number of red-light violations by 25 percent.