From: JForester@cup.portal.com (John - Forester)
Newsgroups: rec.bicycles.soc
Subject: Request for statistics regarding bicycle helmet use in Holland
Date: Sat, 21 Nov 92 12:42:17 PST
Organization: The Portal System (TM)

                       FALLS AND CYCLIST SKILL
   This series of articles has concerned, in part, the theory that
European cyclists don't need to wear helmets because they don't fall
down, while U.S. cyclists need to wear helmets because they do fall
down. The first reason suggested for the claim about U.S. cyclists
was that they were sporting cyclists engaging in what was claimed to
be the inherently dangerous activity of sporting cycling on roads.
While the evidence presented could not, in the absence of definitive
statistics, disprove that claim it showed that it was unlikely. 

   Now Chris Malcolm makes the claim that many of the falls described
for U.S. cyclists were caused by discovering, after years of original
ignorance, the effects of water on the roads. These accidents would
not have occurred to U.K. cyclists who have known of these effects
since childhood because they cycle in wet and sometimes snowy
conditions. Neither the accidents nor the cyclists fit this
description. The discovery about slimy wet wood was that the wooden
bridge decking remained slimy for a considerable time after the road
had dried off. Considering how rare it is to ride on wood, I think
that this is not common knowledge anywhere. As for the cyclists, one
of them had cycled through several New England winters, which are
considerably more severe than those anywhere in the U.K., and in
other years had descended 1,000 feet daily over steep, narrow, twisty
roads that were frequently wetted by the usual nighttime fog dripping
from the trees, while the other had for several years cycled 22 miles
daily in Minneapolis, where snow cover averages 100 days a year.
These are skillful and well-informed cyclists who are not the
ignorant U.S. cyclists hypothesized by Malcolm.

                          CLIPS AND STRAPS
   Chris Malcolm asked how many of the rear-wheel-slide falls
occurred when the cyclists were using toe clips and straps that
prevented them from putting a foot down to stop the fall. All of the
accidents described except the fall on the complicated streetcar
tracks (in 1944, approx.) occurred when the cyclist was using toe
clips and straps.

           TIME VERSUS DISTANCE AS BASE FOR ACCIDENT RATE
   Another writer (who didn't sign his name) argues the hoary,
popular mistake that vehicular accident rates should be measured over
traveling time rather than traveling distance because that measures
"time in harm's way." This base has become popular among bicycle
activists because it lowers the cycling accident rate relative to
other rates. The argument is wrong on two counts: time is not the
proper base and the argument is based on a wrong idea of hazards to
cyclists.

   Time as a base would be accurate only for recreational travel.
That is, considering the probability of accident from one day skiing,
one day pleasure-motoring in the country, or one day cycling for
recreation. However, the object of transportation is to move from one
place to another, and the benefit depends on the destination reached,
not the time spent. Therefore, the proper base for accident
statistics is the act of movement, best represented by distance.

   The argument that the time spent "in harm's way" is the proper
base shows that the arguer does not understand the nature of
accidents to cyclists. It is based on the mistaken idea that the
hazards to cyclists are predominantly cars that randomly attack them,
thus making time "in harm's way" the logical base. The majority of
accidents to cyclists do not involve motor vehicles. Consider falls
on diagonal railroad tracks. If there are two sets of such tracks on
your journey, you face the hazard exactly twice, regardless of
whether you ride fast or slowly. So for all the other hazards that
are not associated with motor vehicles. Now consider the hazards
associated with motor vehicles. The most frequent motorist-caused
car-bike collision is the motorist left turn (right turn in U.K.).
This can occur only where a motorist can turn left and does so when
the cyclist is also in the intersection. Because there are only a
fixed number of such places in any given trip, the analysis is the
same as for other hazards. The only hazard that varies significantly
with trip time is that from overtaking vehicles; the cyclist who
takes twice as long for a given trip will be overtaken by somewhat
less than twice as many faster vehicles during that trip. However,
the hazard of overtaking vehicles is only a very minor hazard that
causes only 0.3% of U.S. urban daytime accidents to cyclists. A
change in that small proportion will not significantly change the
total accident statistics. Therefore the idea that "time in harm's
way" is the proper base for cycling accident rate statistics is
incorrect.

       CYCLISTS' RIGHTS AND BIKE FACILITIES VS ACCIDENT RATES
   The same writer who argued for time instead of distance also
states that it is difficult to compare accident rates between Holland
and the U.S. because of the difference in conditions. He says that in
Holland there are many bicycle paths and "bicycles have normal right
of way" while in the U.S. cyclists have the rights of drivers. The
phrase "normal right of way" is meaningless in this context; to me it
means just what we have in the U.S., the rights and duties of drivers
of vehicles. In Holland, on the other hand, at an intersection the
faster driver has the right of way. That may be "normal" in Holland,
but the prospect unnerves me. However, one purpose of accident
statistics is to evaluate just such differences in laws and
facilities. If the accident rates were much different, we might
conclude that the causes are in the differences in laws and
facilities and investigate to find the specific causes.

                       ACCIDENT RATES VS SPEED
   Accident rates as accidents/distance do not tell the entire story.
Let us suppose (as if we knew them) that the Dutch urban cycling
accident rate is only half that of the U.S. urban cycling accident
rate. Would that mean that Dutch cycling facilities and laws were
safer than those of the U.S.? Not at all. The Dutch cycle much slower
than typical U.S. urban cyclists. Both U.S. and Dutch facilities and
laws are safe enough at low Dutch cycling speeds, but for cyclists
who ride faster U.S. roads are reasonably safe while Dutch bikeways
are incredibly dangerous. The few places where U.S. bike planners
have copied Dutch practices are the most dangerous facilities that I
know, with a car-bike collision rate at equal cycling speed probably
about 10,000 times greater than the rate on normal U.S. roads. I
conducted the experimental cycling for about 4 miles. The average
distance between near-collisions that took great skill to avoid was
0.7 miles, and the last one was so dangerous [just luck that I wasn't
killed] that I swore off all further tests of such facilities.

   Speed is not recklessness and is not to be deplored. Speed is to
be sought and valued. A person can make his or her required daily
travels by bicycle, bus, streetcar or car, and the choice will often
be made according to the time required. The faster cycling is
possible, the more likely it is to be used and the wider is the area
within which cycling is practical. Therefore, the laws and facilities
must enable the cyclist to travel at maximum desired speed, between
all places, in reasonable safety. 

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