Road Deaths increase in NW

[Mike Sales]

That's what I'm saying.

So in this report the metric was number of deaths in six months or whatever. And if you wanted to compare that with another observation that was over a year then you'd normalise both to deaths/ year or deaths/ month. Or some other unit of time.

Deaths per capita isn't useful without that time element.

Jonathan

Well, of course. Did that need saying?

It was stated in the report that the comparison was with "the same period last year."
What changed was the volume of traffic. And the number of casualties.

[Mick F]

Smeed's Law.

Smeed's Law?
Wot's that then?

Looked it up.



Smeed had a fatalistic view of traffic flow. He said that the average speed of traffic in central London would always be nine miles per hour, because that is the minimum speed that people will tolerate.

Intelligent use of traffic lights might increase the number of cars on the roads but would not increase their speed. As soon as the traffic flowed faster, more drivers would come to slow it down.....Smeed interpreted his law as a law of human nature.

The number of deaths is determined mainly by psychological factors that are independent of material circumstances. People will drive recklessly until the number of deaths reaches the maximum they can tolerate. When the number exceeds that limit, they drive more carefully.

Smeed's Law merely defines the number of deaths that we find psychologically tolerable.

[Mike Sales]

Smeed's Law.

Smeed's Law?
Wot's that then?

Looked it up.



Smeed had a fatalistic view of traffic flow. He said that the average speed of traffic in central London would always be nine miles per hour, because that is the minimum speed that people will tolerate.

Intelligent use of traffic lights might increase the number of cars on the roads but would not increase their speed. As soon as the traffic flowed faster, more drivers would come to slow it down.....Smeed interpreted his law as a law of human nature.

The number of deaths is determined mainly by psychological factors that are independent of material circumstances. People will drive recklessly until the number of deaths reaches the maximum they can tolerate. When the number exceeds that limit, they drive more carefully.

Smeed's Law merely defines the number of deaths that we find psychologically tolerable.

These are interesting speculations, I find them productive.
The Law itself is not derived from these ideas, but from observation.

[Mike Sales]

Please could we now return to whether the observed change is as predicted by "Smeed's Law" or the opposite?

Jonathan

As I understand Smeed's Law, it predicts that a lower traffic density will result in a higher casualty rate per vehicle mile. This may well be an increase in casualty rate per head of population, or not.
In it interesting that the much lower number of vehicles in the 1930s caused a much higher road death rate in absolute numbers, and obviously per vehicle.