Roads would be safer without traffic signals


Via Kids Prefer Cheese:

Can you imagine having no traffic lights or signs or any other way of keeping cars and people apart? The results would be dangerous chaos, right?

Well, they have a lot a faith in human nature in the small Dutch town of Drachten. Its main intersection is a busy place, where cars and trucks compete with people on bicycles, and others on foot.

The normal civic response - here and elsewhere - has been to put in more traffic lights, divide the roadway into lanes - control things. But the response in Drachten has been the opposite - they took the controls away.

A funny thing happened. The accident rate around the intersection went down - way down, from more than eight a year to fewer than two. [...]

There have been a few small collisions, but these are almost to be encouraged, Mr Monderman explained. "We want small accidents, in order to prevent serious ones in which people get hurt," he said yesterday.

"It works well because it is dangerous, which is exactly what we want."

The statistics are weak, but the theory has merit. Nonetheless, I would expect some restrictions to be beneficial. When you drive you take into account the risk to yourself, but you only partially consider the risk to others; hence you are not careful enough and some additional incentives are needed (e.g. fines).

Even if these numbers can be replicated, they may mostly reflect a short-term response until people adjust back to their optimal speed/risk ratio. In other words, right after the change risk-averse drivers will be over-cautious until they learn how to drive in the new conditions; the price of speed is high. As time passes and they manage to squeeze more speed out of a set amount of risk, they will probably converge back to their old speed/risk ratio.

And of course the prevalence of accidents is not the relevant metric: a lot of traffic signals serve to co-ordinate drivers rather than make them go safely, and it's a safe bet that stop signals help people go faster on average. The objective is to balance speed with safety, not to minimise the accident rate.

Count me as intrigued but not convinced.

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