Tuesday, 13 October 2009

Flashing lights for school speed zones

I am currently at work on a project to put flashing lights on school zones for times when the speed limit is reduced. It has been noted that the practice of flashing lights is meant to increase visibility of the signs during the times they apply. The trouble is that the drivers start to rely on the flashing to tell them when the signs apply, and thus start to appeal on speeding tickets if the sign does not flash. It was assumed that drivers were conscientiously trying to obey the law and that the lights would make this easier. Instead the opposite has turned out to be the case. It's the law of unintended consequences. You try to draw attention to make school zones safer, but if the signs fail and drivers depend on them, they will be far less safe. It seems a no-tech solution is better from that point of view.

I think drivers should slow down in school zones by default, then check whether the regular speed limit applies. We think of the default in that zone as the higher speed, but it seems safer to me to assume that the lower speed applies until shown otherwise.

Mokalus of Borg

PS - If your counter-argument is "but that's really annoying", then you lose.
PPS - "Annoyed" is better than "I injured some children today".

2 comments:

Stuart said...

I think drivers should slow down in school zones by default, then check whether the regular speed limit applies. We think of the default in that zone as the higher speed, but it seems safer to me to assume that the lower speed applies until shown otherwise.

That's good unless it is 6:30 at night and I am on my way home from a long afternoon at work and people are driving slowly through the 2 school zones on my route home

John said...

At some times of the day, like when it's dark, it should be obvious that the lower limit does not apply, but I always find that I have to spend a good few seconds checking the time of day, the signs and sometimes the day of the week (not to mention the school breaks calendar) before I know whether I should slow down.

It's that time of calculation where I think the slow-down should be by default, because the mental load on the driver increases, meaning slightly less attention on the road. The goal of the timed flashing lights is obviously to reduce that mental load, but it has some unfortunate side-effects.

I don't think the best solution has yet been found, and that includes my own no-tech, slow down by default suggestion.