skunkylee

Hi!

How do the automatic fault detection systems work inside traffic lights?

There was an accident where I live a couple of days ago where the red light bulb malfunctioned on the pedestrian crossing (didn't light up) and a kid got hit by a driver going through green. Sadly, the boy didn't make it.

I'm guessing the lights are connected to a network. For instance, how difficult would it be to place current detecting sensors for the power lines going to the bulbs and have them report a malfunction when there's no current flowing where there should be.

Barring that, what kinds of systems or safeguards are implemented?

Thanks for the AMA :)

Hah, thanks! My generation has been practically raised on Cartoon Network. Add compulsory English classes which started at the 4th grade, the fact that visual media is subtitled, not dubbed, throw a healthy dose of Internet in the mix and you'd be a bit hard pressed to find someone from my area who isn't at least passably proficient in English. :)

I live in the approximate center of the a very small country, though. People my age who lived near the border with Italy were snagging Italian dubbed cartoons on their TV channels and are at least acquainted with spoken Italian. It goes pretty much the same for those living near the border with Austria and were watching cartoons dubbed in German. Most of them are quite good with the language.

[edit] Just to give you a perspective of how small of a country are we talking about. Imagine I live in the center. I need approximately an hour and a half of easy driving if I want to get to Italy and 2 hours if I want to get to Austria with no hurry. Actually, I can get to Austria in under an hour if I take a mountain pass.

AAAaaaand, I'm way off topic. ;)

A quaint central European country of Slovenia. :)

I didn't really want to pull any attention to the accident, it's just that I heard about it a couple of days ago and since I'm an EE, it got me thinking about the fault system implementation in traffic lights.

And lo-and-behold, this thread gave me the perfect opportunity to ask someone with first-hand experience. Thanks for the answer. :)