ROANOKE, Va. -

You may not notice them until you notice them; cameras mounted on top of traffic lights.

They're popping up all over the Roanoke Valley.

Many of the newer lights in some busier intersections have gotten new lights within the past few years.

Jutting out from these bars pretty prominently are cameras.

Their function? They're the new sensors at stop lights to help time traffic lights.

The older lights hang from wires and those are tripped by sensors underneath where the car stops.   

Important to note, these cameras are not used by police to catch people who run red lights.    

They fall under the purview of the Virginia Department of Transportation and we're told the cameras make things much easier.

Those cameras aren't high-resolution enough to take pictures of license plates.