From: JForester@cup.portal.com (John - Forester)
Newsgroups: rec.bicycles.soc
Subject: Request for statistics concerning bicycle helmet use in Holland
Date: Wed, 18 Nov 92 07:47:57 PST
Organization: The Portal System (TM)

   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. The US data come from three studies: one of children in
elementary schools, another of college-associated adults, the third
of club cyclists. The proportion of car-bike collisions among all
accidents for these three groups is:
young children: 10%
college-associated adults: 16%
club cyclistss: 18%

   The college-associated adult reported that their fall rate per
ride is 6%. That struck club cyclists like myself as absurd, but that
is the proportion who answered yes to the question: On your last
ride, did you fall?

   While it is true that US cyclists are considerably less competent
than they should be, there is no particular evidence that sporting
training and muscular effort are the causes of their accidents. The
college-associated cyclists are largely campus commuters who don't
ride fast. The children, of course, are largely play cyclists, and
they suffer the consequences of playing on bicycles.

   More to the point, the data for club cyclists (Kaplan, Jerrold A.;
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. Incidentally,
most racing in this period was done on roads on which motor traffic
was only slightly controlled, generally only to allow cyclists the
right of way when approaching stop signs. 

   The same study compares the accident rates for the same cyclists
on different types of facility. For example:
Major street:       114.2
Minor street:       104.8
Bike path           291.6

   Just think about those statistics.

   Furthermore, consider the following accidents in my own family.
Riding at walking speed in a 49" gear on a university campus among
many pedestrians I saw an opening ahead and stood up. Because the
surface was damp with morning dew the rear wheel spun. Because the
walk had a high crown the rear wheel slid to the side and down I
went, acquiring a surprisingly large and painful abrasion. 

   On a descent in the Berkeley hills on my way to campus I traversed
a wide curve, going at a normally safe speed, as I had done many
times before. However, the bus terminus had been changed to this
location, and the buses waiting for the start of their return trip
had deposited grease on the roadway that had been clean before. Down
I went. 

   I was crossing a wooden bridge, one that I had crossed many times
before. Because the road curved just after the bridge I made a very
slight adjustment of course while on the bridge. Down I went. I
discovered that when wooden bridges have been damp for more than
several days (not frequent in the California climate) they get
covered with algae and are as slippery as glare ice. 

   One rainy day I was crossing an intersection at which there was a
multitude of streetcar (tram) tracks. There were double tracks on
both streets with facilities for turning from any direction to any
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.

   I had spent a morning directing a TV news crew shooting my
performance of instant turns while a car, driven by an expert
pretending to be incompetent, turned right and turned left directly
at me. Putting yourself into and then extricating yourself from a
life-threatening situation time after time until the camera records
the greatest impression of danger somewhat tires the brain. I then
set off across a city I had never been in before to meet my cycling
companions for lunch. The road I was on had been recently repaved. At
one intersection, with stopped cars waiting on my right and moving
cars at my left shoulder, I drifted off the new paving onto the
surface of the intersecting road. With no room to make a curve to
perpendicularly approach the step back up to the new paving I should
have stopped, but, probably being mentally tired and being distracted
by route-finding in a strange city, I tried to maintain my course. My
front wheel would not climb the 1.5" step at that acute angle and I
went down, thankful for my helmet as I heard it banging over the
pavement until I stopped. I broke two ribs, painfully bruised the
inside of my hip joint, and put two cracks in my pelvis. While I
could still ride, for several weeks I had to use crutches for
walking.

   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.

   She was riding on the road behind the Stanford campus and,
evidently, hit a small rock, although we never found it. The impact
bent the fork crown, she went down, landing on her head. Her helmet
prevented head injury, but the impact wrenched her neck and she has
had pain between the shoulder blades when riding.

   While crossing a ford of flat granite slabs in the Cotswolds, a
ford that I had successfuly negotiated, she failed to ride exactly
straight and slipped sideways and down on the algae that covered the
slabs. Her bruised hip was uncomfortable for the rest of that holiday
tour.

   Sure, I have been in one bad racing crash when everybody ahead of
me went down and I couldn't turn aside, and twice I have put myself
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
tired. 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. My
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.

   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.

JForester@cup.portal.com               John Forester
                                       726 Madrone Ave
408-734-9426                           Sunnyvale CA 94086 USA