Can emergency vehicles change the traffic lights?
Yes. Many cities have installed a system where emergency vehicles can change a red light to green. Each vehicle is equipped with a small light emitter. To the eye this looks like a rapid camera flash. A receiver on the traffic light pole will sense the special frequency of flashes and turn the light green for that vehicle, and red for everyone else. These can ‘t be used just to get around town for several reasons. Many of them are connected to the light and sirens. It is not on unless everything is on. They also keep a record of each use. More information: http://www.cedarcity.org/ccfd/news/opticon.
