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COMMENTS

(Work in progress!)

Intro

Three of the 4 Es of bicycle programs are listed; this is an early description of them.

An excellent description of the bikeway controversy

02

The small percentage of cyclists in Washington, DC probably also reflects the low average income in that city due to its being almost entirely urban.

03

*** The figure of 82% of fatalities resulting from bicycle/motor-vehicle crashes -- in 1975, before the advent of off-road bicycling --   is lower than the often-mentioned figure of 90%.

*** Regarding the statements about the unreliability of data, there is still no good comprehensive report on bicycle use and non motor-vehicle crashes in the USA in 2004.

*** The figure for bike-bike collisions in Santa Barbara is far higher than in the other studies, and apparently, as described in the text, reflects that much cycling there is on separate paths. The comment that the system of paths there is excellent is open to question given the number of bike-bike crashes.

04

*** John Forester indicates that the proportion of urban and rural crashes in the Cross and Fisher Study is inaccurate, and has published revised results reflecting this observation in his book Bicycle Transportation Engineering. His correction significantly affects the importance of various types of crashes.

*** The lower crash involvement of bicyclists between 30 and 59 years of age may result from less mileage and also greater experience. This study can not determine which, as it did not record those factors. Contrast with the Kaplan and CTC studies, which clearly identify years of experience as factors in reducing cyclists' crash rates.

The finding that cyclists involved in crashes were experienced supports John Forester's statements that experienced bicyclists account for most bicycle use, in spite of the much larger numbers of casual, infrequent bicycle users. However, the percentage of cyclists involved in crashes who had ridden their bicycles less than five times preceding their crash is probably far higher than that in the general population.

*** The finding that all but one of the bicyclists who were violating the law knew they were violating it is interesting. Present (2004) conditions may be somewhat different.

*** There is no reference in Table 12 to the footnote below that table.

Data showing that trucks are involved disproportionally in collisions with bicyclists ought logically to apply to SUVs.

It is suggested that the finding that lightweight bicycles are involved in more crashes results from their being ridden at higher speeds. Another and possibly more credible hypothesis is that they are ridden farther per year in use.

The statement that 5% of headlights and taillights were defective does not agree in wording with the graph in Figure 5, which shows that only 20% of bicycles were equipped with headlights or  taillights, and about 25% of these headlights and taillights were defective.

The recommendation for a safety flag would be contested by many bicyclists, particulary those who ridei n groups. A brightly-colored helmet serves much the same purpose. But helmets are not mentioned anywhere in this chapter, even though proper bicycling helmets had been available for four years at the time of the writing!

The suggestion that no improvement in equipment except for brakes would have a significant effect on crash  rates could not apply to bicyclists who ride much at night and would be less aplicable to non-motor-vehicle crashes than to the crashes this study examines.

The finding that many fewer crashes per trip occurred on recreational trips is  interesting. It may reflect the choice of routes, the type of cyclist making these trips, and the length of the trips.

John Forester has performed an analysis showing that the Cross/Fisher study does not properly reflect the proportion of urban vs. rural crashes relative to the general population of bicyclists. This is available in Forester's book Bicylce Transportation Engineering.

05

That all the multiple-threat collisions occured in California, where motorists yield to pedestrians, indicates the hazard of motorists' treating bicyclists as pedestrians -- a growing phenomenon. "...act and are treated..."

"Even the youngest ..." mentions only that bicyclists are required to yield at yield signs and stop at stop signs. Does not mention yielding at stop signs.

"Although..." It is interesting that this information on the type of bicyclist error as well as much other information in the report is presented more or less as hearsay, without numeric data to support it. In this case, as in most cases, Cross is correct. But it is John Forester who re-examined the data in this report to look at crash types according to the type of bicyclist or motorist error, bicyclist age and rural/urban location -- information which is presented in fragmented and anecdotal form here.

"The median age..." Some results of statistical analysis are reported here, but it is necessary to have the Cross and Fisher report to obtain the full statistical analysis -- in this case, for example, giving both the high and low age limits.

In connection with problem type 7, as well as others, there is no mention of the bicyclist's position on the roadway other than riding with or against traffic. Problem type 7 is one in which riding farther form the edge of the roadway would increase the time and space available ot avoid a collision.

Other Class B: it is interesting that entering the intersection well after the start of the red signal phase led to so few collisions. This finding supports the conclusion that many signals remain red much longer than they need to when there is no cross traffic, and that traffic signal actuators and timing that respond properly to bicycles as well as motor vehicles would help avoid this problem. This conclusion also explains the strngth of the temptation for bicyclists to run red lights.

05a

The percentage of car-door collisions in the report as a whole is low. But the percentage in Washington, D.C. is more nearly the same as that in other studies conducted in areas where on-street parallel parking is common.


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Contents copyright 2004,
John S. Allen