Thursday, April 23, 2009

20mph statistics

Yeah still on this and what keeps getting quoted is the DoT's - for pedestrians being hit at 20mph 2.5% of accidents are fatal, at 30mph 20% are fatal, at 40mph 90% are fatal.

What I can't seem to find is anyone who actually links to this research by the DoT rather than just quote it. Digging through their site I can find that the number of accidents caused by inattention/distraction are double those caused by excessive speed/dangerous driving (p36) and remember that "excessive speed" includes those that are within the limit, but conditions would suggest a lower speed being used.

I can also find the Ashton and Mackay (1979) study being quoted a lot. But surely they can't be using a study from 1979 as the basis for these statistics.

I can find the statistics for car driver deaths as factored by speed.

What I can't find is those figures all the media are using. Oh silly me I should be looking through the Press Releases. Has to appear under Making Britain's roads the safest in the world mustn't it - nope. Transport statistics - nope.

Ah-hah the February Transport statistics has Road Casualties in Great Britain got to be there - ye...nope. It has the casualty rates, just doesn't show any speed factors

It's odd that I can find casualties by road class and condition and for those in the vehicle, but not for pedestrians. Perhaps I'm just not looking in the right places, but you'd kind of expect a statistic being quoted so prominently to feature in an easy to find place, like um a Press Release?

I've even tried the National Statistics site with a keyword search of "death speed road" and got nothing useful.

[Update 24/4 - Ah hah I've finally found an official quote stating that at 40mph the fatality rate is 85%, at 30mph 20%, and 20mph 5%; which isn't what's being quoted. Oh goody "Government research has shown:" precedes it; with no link to said research. Oh well as it's the government telling us this it's got to be true and accurate; not as if they ever make a mistake or 'accidentally' misinterpret the raw data.]

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