Ask Patch: Those Devices On the Traffic Lights...

Last week a reader asked about those devices on top of the traffic lights at Armistead Road and Route 1.

We had a couple of great suggestions, one of which was by Robert Lee, and his was on the money. Robert suggested that the devices allow first responders to change the light as they are approaching an intersection.

Ellen Kamilakis at the Fairfax County Department of Transportation confirmed Robert's accuracy: “These are emergency preemption devices. The unit pictured recognizes the strobe pulse from the emitters that are located on Fire and Rescue and transit vehicles.”

Thanks Robert and Ellen!