On my way to work a bridge is being repaired. Today I was in the stream of traffic heading towards town, no cars going the other way. Mid stream the lights went red, just as I reached them. I went through. I reckon I travelled 100m between the lights and then about 600m up the hill before the lights changed.
I realise there has to be a margin to be sure a car gets through, but how big should the margin be?
Why when the lights have sensors do they never seem to be switched on? It just looks like a crude timer is used.
Under what circumstances are the sensors on the lights used?