I Wonder: What are those blue lights on stoplights?

Credit: Trevor Loucks/KTVB

These small lights on local stoplights allow cops to help nab red-light-runners.


by Don Day KTVB.COM

Bio | Email | Follow: @DonLDay


Posted on May 13, 2009 at 10:42 PM

Updated Sunday, Oct 25 at 2:57 PM

What are the tiny blue lights on the backside of the stoplights?-Steve Clelland

Stoplights are a simple concept - green means go, yellow means slow down and red means stop. But blue? Blue could result in a ticket and a fine.

Blue lights have been added to 40 traffic signals around Ada County, and are used to help police officers catch drivers who are running red lights.

Here's how it works: As a driver approaches a red light at an intersection, a blue light shines on the back side of the traffic signal. An officer can safely sit on the opposite side of the intersection and wait. If the driver runs the red and zooms through, the officer would see the blue light and could safely pull over the driver without having to run the light as well. ()

"It's a way for an officer to be at a better vantage point," Boise Police spokesperson Lynn Hightower said. "If an officer is behind the light, they can't safely pull someone over."

This way, an officer can wait in a safe location, and if someone zips through the light without stopping, an officer can make a traffic stop.

"As it is getting around to more intersections we're using it more. Patrol officers and traffic officers alike are both using it," Boise Police Officer Richard Burch said.

The blue lights help police cut down on what can be a very dangerous crime.

Hightower says the most common place for traffic accidents is at intersections - and running a red light is the most cause of accidents at those intersections.

"(The lights) are out there for officer and motorist safety and efficiency in enforcing traffic violations," she said.

Officers can't watch every light at all hours of the day, so they look for a pattern of accidents or complaints from nearby residents or businesses to decide which intersections to watch.