News1 min ago
Traffic Lights
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When stopped at temporary traffic lights at night (Road works etc) you often see people flashing their lights at the red light to make them change to green quicker. Does this actually achieve anything or are the lights just changing on a fixed time sequence?
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For more on marking an answer as the "Best Answer", please visit our FAQ.Another urban myth flashing your lights does nothing at all to the traffic lights. They are on a timed sequence . Some lights have a traffic detector that senses an approaching car and changes the lighs to let it passed if the traffic is very light, for instance in the early morning, but even then flashing your headlights does nothing as it is a movement sensor similar to those door lights you see that come on when someone gets close.
You may often see it, I never have.
If it achieves anything it is a false sense of control given to the driver who may then continue their journey in a slightly less dark mood than they otherwise would.
What I want to know is that given that it is now 2012, how come we still have traffic lights that appear to sense your imminent arrival so they can go red and hold you up, until someone comes along in the other direction and then the lights change apparently to hold them up ? Surely by now we can expect (artificially) intelligent behaviuor from our lights ? Or how about the number of times, when no traffic is about, the lights opt to switch for no apparent reason so the direction least likely to produce the next car is at green ?
If it achieves anything it is a false sense of control given to the driver who may then continue their journey in a slightly less dark mood than they otherwise would.
What I want to know is that given that it is now 2012, how come we still have traffic lights that appear to sense your imminent arrival so they can go red and hold you up, until someone comes along in the other direction and then the lights change apparently to hold them up ? Surely by now we can expect (artificially) intelligent behaviuor from our lights ? Or how about the number of times, when no traffic is about, the lights opt to switch for no apparent reason so the direction least likely to produce the next car is at green ?
I've worked with roadworks in one capacity or another for over 25 years TWR and you definately cannot change the lights by flashing at them. They are microwave sensors on top of the lights (so work on a wavelength of around 10cm) whereas wavelength of light is a bit shorter than that!!, so no effect. The sensors have probably detected you at the same time you flash your lights...its coincidence.
Old traffic lights in America did detect flashing lights to detect emergency vehicles approaching, but this system has never been used in this country, also they detecting strobe lights, not slowly flashing lights, so you wouldn't have been able to trigger even the old American lights unless you could flash your headlights at more than about 15 times a second.