From: rlewis@muskwa.ucs.ualberta.ca (Robert Lewis)
Newsgroups: rec.bicycles.soc
Subject: Re: Risk ratio (was: Ticketing illegal cycling)
Date: 5 Nov 92 06:08:28 GMT
Organization: University Of Alberta, Edmonton Canada

drobinso@mendel.une.edu.au (D.Robinson) writes:

>                                    In Britain, I know from being carted to
>hospital after one of the 4 times I've been hit by a cars, that they
>include all hospital reports of accidents in the official figures.  So
>a bike-bike accident resulting in road rash, broken bones, wounds etc
>should get counted.

That may be your experience from one trip to the hospital, but the
published reports from the U.K. would seem to indicate otherwise.  The 
British Medical Association in summarizing the literature on cycling
accidents comes to a different conclusion:

	The principal problem is the extent to which the under-reporting
	of accidents varies with different travel methods, situations,
	and severities of injury.  There is much evidence that people do
	not always report cycle accidents.  Several studies have
	compared the number reported by the police with the number
	treated in hospital for injuries.  The findings of these studies
	were fairly similar.  A more recent study showed that 74 per 
	cent of the slight reportable accidents' and 61 per cent of the
	'serious reportable accidents' go unreported.  (British Medical
	Association 1992:48) 

>>Forester (1988:166) estimates
>>that they are about as common as car-bike collisions.  An article in the 
>>September issue of "Bicycle USA", the member magazine of the League of 
>>American Wheelmen, by David Egan entitled "What Causes Bicyclists to Fall" 
>>says that collisions between bicycles account for 26% of falls where as
>>collisions with automobiles account for 10%. 

>But there are various reasons for separating out accidents to kids playing
>with their bikes (where education and cycle proficency training might be
>needed) to the experience of the average adult using a bike to get from A
>to B.  The latter is probably of more interest to the net reader, but
>this bears no relationship whatever to the figure of 26%.

True enough, but I think that that explains the difference between
Forester's data and Egan's rather than explaining away the observation.  
Forester's data would seem to come from interviews with experienced 
cyclists (Forester 1984:166-167) and he finds that car-bike collisions 
account for 17% of all accidents and bike-bike collisions for 17%.  Egan's 
data would seem to come from a broader sample and as a result he finds 
that car-bike collisions account for 10% of all accidents and bike-bike 
collisions for 26%.  This would be consistent with a population made up
of more 'kids playing' and other sorts of inexperienced cyclists than
found in Forester's study.  Of course being an experienced cyclists does
not protect one from the actions of inexperienced ones, i.e., it is not
possible to disentangle the experience of both groups as I suspect that
many of the accidents which occur involve the tangling of experienced and 
inexperienced cyclists.

>For example, of the 239 bicycle accidents in the Metropolitian Police survey 
>(where other road users were considered mainly to blame twice as often as not - 
>mentioned in previous post) only one involved another cyclist, and he wasn't 
>injured.  This compares with 8 pedestrians, a dog and 204 drivers or motorbike 
>riders (4 of whom were injured i.e 2%, compared with about 91% of the cyclists).

As the BMA study suggests, and fairly consistant with the North American
findings, the accident reports of the police are unreliable as regards
cycling accidents.  I would guess, and again the North American
literature supports this, that the pattern of non-reporting is not
random.  It is clear that accidents involving fatalities and motor
vehicles are probably mostly reported, as a result bicycle accidents
appear to make up a larger proportion of accidents than they actually
do.  Accidents involving motor vehicles are also more regularly reported
than other accidents.  Stutts et al. (1988) report that "Although motor
vehicle are only a factor in about one-fifth of the emergency room
cases, virtually all of the police reported cases involve collisions
between bicycles and motor vehicles." (65)  I have seen no evidence that 
such is markedly different in the U.K.  Such is not really surprising,
people report accidents for a reason, not simply to help the police keep
nice records.  People report car-car collisions, even when no injuries
are involved, because of the damage sustained by the cars and the desire
of the not guilty party to get the other or the other's insurance agent
to pay for the damage.  [Note the following is a hypothetical situation
only, it has not happened to me, it is intended entirely as logical
exercise]  If I were a cyclist who ran a stop sign and into a truck, 
breaking my arm and doing little or no damage to that truck (which he 
probably would not be able to collect on any way or would only be able 
to do at some bother and expense, probably beyond the extent of any 
minor damage), I would most probably not demand that the police be
called so that I could get a traffic ticket.  Rather I would, sensibly,
simple appologize and go to the hospital myself.  If on the other hand
it was the trucker who ran the stop sign, as an injured cyclist and with
a damaged bike I would have very much of an interest in having the cops
show up so that that truck driver could pay for my personal and
equipment damages.

>Or I could quote from a survey of accidents to members to a cycling 
>organisation in Edinburgh, in which I participated.   We were asked to report
>any incident in the past year which resulted in the rider coming off his bike.
>This resulted in 98 accident reports, but not a single bike-bike collision, 
>even though some members would have been regularly riding in groups and some
>were kids.  Of the serious accidents, obstacles/holes in the road caused 22%, 
>icy conditions 4%; the remainder were cars (60%) and pedestrians or animals 
>into the road (14%).

As I have not seen this study I can not comment on either its results or
methodology, though if the study correctly represents the conditions
in Edinburgh then Edinburgh is quite different from any other areas
of the world which I have seen studies of.

>If bike-bike accidents on segregated cycliways are a serious problem 
>in some parts of the world, then why not direct campaigning effort towards 
>upgrading the paths - adequate widths, centre dividing lines and improved 
>road crossing facilities?  Compared with the cost of the original construction, 
>wouldn't this be relatively cheap?

It is questionable if such is possible, I have never seen any designs
which have shown an increase in cyclists safety especially at
intersections (where it is most important).

References:

British Medical Association (1992).  Cycling Towards Health and Safety.
	Oxford:  Oxford University.

Forester, J. (1984).  Effective Cycling.  Cabridge, Mass.:  MIT.

Stutts, J. C.; J. E. Williamson; and F. C. Sheldon (1988). 
	"Bicycle Accidents:  An Examination of Hospital Emergency
	Room Reports and Comparison with Police Accident Data." 
	Transportation Research Record, no. 1168, pp. 60-71.

_________________________________________________________

Robert M. Lewis
Department of Sociology
University of Alberta
Edmonton, Alberta
Canada