photosensitive stoplights?!

[mrfoo]

I know this may sound ridiculous and I still think it is but I had a friend ride with someone last night and this guy driving flashed his lights a certain distance from stop lights and somehow they changed everytime he got there. He told my friend that there is a photosensitive light cell in each of the stop lights that enables them to change when they sense the flashing lights of an emergency vehicle. I told him this guy was full of BS and that if anything the trip wires changed the light in their favor. If anyone could clarify if there actually IS or isnt a photo cell in a stop light I would appreciate it.

I hope that makes sense.

 

[Rev Den]

The system is called Opticom and is simaller to a strobe light that mounts on an emergency vehicle. A detector mounts on the stop light and watches for the flashing strobe at a certain frequency, when it detects it it changes the thru light to green and the opposing lights to red. Some systems incorperate a white bulb on the traffic signal to show the system is activated. It is doubtful that you buddy flashing his car headlights could do the trick.

Rev

Opticom

 

[Kejtar]

hmm time to invest in a mini strobe I think : the lights from the street that I use to get onto the bigger street never seem to be green and the wait is LOOONG and I have to make a left so there is no way to escape them

 

[Bronco638]

Flashing your lights at the sensor does work, I've seen my brother-in-law do it. BUT, it's difficult to get the flashing pattern just right and IF you get caught, you're in BIG trouble (at least in Illinois you are).

D.

 

[woody]

I read something where a guy was selling (a copy of) the device that some EMS vehicles use to switch the lights to clear a path...

I doubt it remains 'legal' for long, if it ever was for non-EMS use.

NC outlawed those semi-clear license plate covers that 'obscure' the markings from photo-radar & red light cameras, so it wouldn't surprise me if they move on this pretty quick.

My town only has two signals, so it's not that big a deal to sit a spell.

 

[bgcntry72]

Try this out

Check this out.
And this.
Almost all of the traffic lights in Metro areas have this technology. Emergency and police vehicles have an interface in the wiring to have the lights synch up with traffic control lenses. In some cases, there is even a white light on the traffic signal to indicate when it is receiving a pre-emption signal.
I have seen these sporadically on EBAY, and some manufacturers abroad are trying to import them. Possesion and use by civilians is a serious offense, and from what I understand, very costly. One of the manufacters has vowed to sue anyone using their product in an unauthorized manner. The loophole is that the devices use infrared instead of radio waves, skirting any kind of jurisdiction issues.
Do a search on illegal traffic preemption, amazing stuff.

 

[TiRod]

Abuse it enough and they will encode the activation signal beyond simple headlight flashing - which one court says is legal communication under the First Amendment free speech, in a case against a motorist flashing oncoming cars about a speed trap.

Ain't this fun?

 

[RichP]

At least in this area of NE PA they are mounted on the traffic signals themselves, they are about the size of a small bird and have two or more lenses. Yes, you headlights will kick them and the fine I've heard in this area is $500 + points. We have one set of lights that come off a side road with them up there, they also set the pressure plates in the road so that any vehicle coming on that road triggers the change immeadiately even if it has just changed back, a real PIA as it backs traffic up on the main road.