Comment by bloak

4 days ago

I've sometimes wondered what the exact rule is with red lights. Presumably you're allowed to continue moving forwards if the front of your vehicle passed the stop line before the light turned red. But if you stopped with the stop line passing through your vehicle are you allowed to start moving forwards again while the light is red? (Whether that would be a sensible thing to do would depend on whether you're driving a long vehicle with just a tiny part of it behind the stop line, or a motorbike with just a tiny part of it in front of the stop line, but does the law distinguish those two cases?)

I don't think the law is so specific, but I suspect the right interpretation would be that you should pass through the intersection if the car is in a position where it would block other traffic the moment the light turns red; in any other circumstance, you should stop if the light is red, even if you passed the location where you'd normally wait.

For example, say you're entering the intersection on green/yellow, but the car in front suddenly stops while you're on the crosswalk, possibly not even seeing the light on the side of the road, but no part of your car is impeding the cross traffic. Well, even if the car in front now clears the intersection, if the light has turned red, you should almost certainly stop and wait for the next green light, rather than trying to clear the crosswalk: doing anything else is much more dangerous.

If your vehicle is ever fully stopped past the line, and the light is red, that would be considered a “blocking the box” traffic violation in most jurisdictions. You technically should not have entered the intersection at all without the ability to fully clear it.