From: cam@castle.ed.ac.uk (Chris Malcolm)
Newsgroups: rec.bicycles.soc
Subject: Re: Request for statistics concerning bicycle helmet use in Holland
Date: 19 Nov 92 02:18:15 GMT
Organization: Edinburgh University

In article <69759@cup.portal.com> JForester@cup.portal.com (John - Forester) writes:

>   Chris Malcolm suggested that the reason why 8/10 (approx) of
>accidents to cyclists in the US are not car-bike collisions is that
>US cyclists are mostly "young people with sporting ambitions ...
>partly due to overstepping the limits and partly due to not paying
>attention because too absorbed in strenuous muscular effort" followed
>by the statement that "doing sporting cycling on the same roads as
>cars strikes me as horribly dangerous." That suggestion is largely
>incorrect.

>Characteristics of the Regular Adult Bicycle User; MS thesis U of
>Maryland, 1975) show the reverse of Malcolm's suggestion:

>Type or purpose   Accidents/million miles   Serious A/million miles
>Work/School              97.7                         24.4
>Recreation/Touring      114.1                         34.1
>Utility                 184.3                         43.5
>Exercise                100.6                         28.9
>Racing                  115.4                         25.6

>   From this you see that the most dangerous cycling is that for
>utility purposes, short trips around town, while commuting is the
>safest, and recreation/touring, exercise and racing are practically
>indistinguishable for all accidents and, for serious accidents,
>racing is practically indistinguishable from commuting.

This shows that the accident rate for US utility rides is nearly twice
that for exercise rides. This neither contradicts nor confirms my
suggestion that a lot of accidents are due to "young people with
sporting ambitions". Of course the utility rate will be worse -- it
takes place in the most dangerous conditions. What I meant to suggest,
perhaps not clearly enough, was that the US biking culture was
exercise/sport oriented, so that when a US cyclist rides off to
collect a pint of milk -- a utility ride, he/she is more likely to
take the opportunity to work up a sweat and a good speed while doing
it.

The only UK bicycle stat I have to hand is .08 deaths per million
miles.

>   Furthermore, consider the following accidents in my own family.

>Because the
>surface was damp with morning dew the rear wheel spun.

>had deposited grease on the roadway that had been clean before.

>discovered that when wooden bridges have been damp for more than

>other, so there was a great deal of grooved and slippery steel across
>the intersection. Down I went. Carelessness, maybe, but it was still
>a difficult place when wet.

>front wheel would not climb the 1.5" step at that acute angle and I

>   My wife came to a stop at a traffic signal in the dark, but her
>rear wheel rested on an oily patch. Because of the crown of the road
>her rear wheel slid sideways while she was stopped, and down she
>went, just as I had done 30 years before.

>hit a small rock

>failed to ride exactly
>straight and slipped sideways and down on the algae that covered the
>slabs.

>   Sure, I have been in one bad racing crash when everybody ahead of

>down by mishandling the handlebars while trying to catch an item of
>food or a water bottle that slipped from my hand while eating and

>And I have been hit once by a left-turning car, while riding
>to work, and once by an opening door while making a utility trip.

>family history is typical, and its evidence does not show that our
>non-motor-vehicle-associated accidents, or our car-bike collisions
>for that matter, are largely tied to the factors that Malcolm
>suggests.

Factors: water 4; grease 2; rock 1; pack 1; eating and drinking 2; cars 2.

Solo: 9; other vehicles: 3.

>   I suggest that it is very likely that the actual accident pattern
>for many European cyclists, when it is investigated, will show a
>pattern much more like the known American one than some European
>activists like to think.

An interesting and informative post. I'll post more detailed UK bike
stats later. In the meantime I'll simply observe one probable
difference: in the six months between the autumn and spring equinoxes,
in many parts of the UK it is rare for the roads ever to be completely
dry. They vary between damp, wet, sloshing with water, frosty, and
occasionally some snow and ice. Cyclists in these conditions don't
make the kind of discoveries via accidents about wet wood, steel, etc.
that you mention: they have known these things so well for so long
they can't remember not knowing them.

One thing puzzles me about your accident reports. In some cases you
mention a fall off because the rear wheel slid out. Were your feet
caught in clips? My experience of rear wheel slides is that they are
either recoverable, or you can simply put your foot down and become a
sort-of-stable sliding/hopping tripod until you stop.

I don't know how typical I am, but I've spent about twenty years in
which a bicycle was my only personal means of transport. I've had one
accident with a car, and one with a wall -- in both of which I
remained astride the bike. I can't ever remember falling off, once I'd
learned to ride. I certainly have never hurt myself beyond a bruise.
-- 
Chris Malcolm    cam@uk.ac.ed.aifh          +44 (0)31 650 3085
Department of Artificial Intelligence,    Edinburgh University
5 Forrest Hill, Edinburgh, EH1 2QL, UK                DoD #205
Newsgroups: rec.bicycles.soc