How to change traffic signal with your headlights

Dear Matthew AIice: My friend Billy seems to think that if he flicks his high beams on and off, he can trigger a sensor on traffic lights and cause the light to turn green. He thinks the sensor registers the number of sets of headlights of vehicles and that his flicking his lights tricks the sensor into thinking there are more vehicles there than there are.... — John Rambo, Normal Heights

Dear Matthew Alice: My boyfriend claims traffic lights can be changed by the police through a remote-control device. I’ve also heard that signal lights can be changed by turning car headlights on and off rapidly. I think it’s all bogus.... — Trish in La Mesa

I am curious about some apparatus appearing on traffic signals around town. These appear to be cylinders with a protruding tube. I’m told these are photo radar devices and that only those intersections with antennae visible on at least one corner are the real ones, the rest are fakes.... — O.E. Pepper, the Net

Dear Matthew Alice: Many of the traffic lights around town have small projections that look like cameras [and] may be monitoring speed and those dorks who try to beat the yellow or run the red.... — John Carlisle, Sharp Rees-Stealy Urgent Care

Obviously this question needs some urgent care too. The Big Brother-ish tubes and antennae are part of the Opticom signal-override system that allows ambulances and fire engines to maneuver safely through traffic. Police don’t have them because few of their calls are potential life-and-death matters, and a patrol car is more maneuverable than bulky emergency vehicles. The driver flips a switch to activate a strobe on the front of the vehicle, which flashes at a specific high frequency, the tubes read the strobe and switch the light to (or hold the light on) green. It can control lights for many blocks if there are no visual obstructions between the strobe and the tubes.

Yeah, yeah, I know. You have a friend who knows somebody who has actually changed the lights green by pulling up to an intersection and flashing his headlights. Well, tell the fool to pull up to a controlled intersection, blow his horn three times, spit out the window, then turn on his windshield washer full blast. I guarantee you the light will turn green. The boob has tripped the road-surface sensor, telling the traffic light a car is waiting for a green. This cause-effect stuff is pretty tricky....