Small, blue lights have sat on top of traffic signals for some time now.

And while there has been some confusion regarding the purpose of the lights – including whether they were installed to help colorblind drivers – the main purpose of the blue lights is to help police catch red-light runners.

The lights were originally white or clear before they were converted to LEDs with a blue hue. The technology allows officers to be sure which directions must stop or yield at an intersection crossing and increases safety for both the public and police officers. The blue lights are active whenever a traffic light is red.

With this, officers patrolling certain intersections can wait in a spot that is safer to pull out if they have to catch a driver who ran a red light.

“With those confirmation lights – that’s what we call them – drivers don’t have an excuse,” Gainesville Police Department spokesman Officer Ben Tobias said. “It’s a way for us, no matter where we are on the intersection, to prove that the light was in fact red.”

This story is a part of Untold Florida, a WUFT News series built from your questions.