I heard the Walt Bodine Show today and it was great to hear so many people calling in to support bicycle facilities.
One thing I think was clear from the show is that we need to do a MUCH better job getting out the information about the safety of on-street bicycling.
Arguments about safety such as those made by Councilman Ford have been disproven by the hard data, long, long ago.
Let me summarize what is know by hard data:
1. Bicycling on-street is safer than cycling on off-road paths
or sidewalks.
2. Major roads are not necessarily more dangerous than minor roads.
In fact, major roads can be safer for bicycles for the same reason
they are safer for cars (better sight-lines; protected from cross-
traffic (the main cause of accidents); intersections better-controlled).
3. Well-designed on-road bicycle facilities can, in fact, slightly
increase safety of on-road cycling.
4. The dreaded "rear-overtaking" accident is, in fact, pretty uncommon
and we shouldn't let it dominate our discussion of on-road cycling
safety.
For more information, data, and sources to back up these "strange and wild" claims, read on . . .
- - - -
In _Effective Cycling_, John Forester tells the story of how motorist groups in California commissioned a study whose purpose was to demonstrate how dangerous on-road bicycling was, so they could ban cyclists from the streets and channel them into off-road bike paths--the very same type of argument made by Councilman Ford.
Their first study showed the exact opposite of what they wanted to hear. In fact, on-street bicycling, even on busy streets, was a couple of times safer then off-street bicycle paths.
Assuming that their small initial study must be wrong, the motorist groups commissioned a much larger, nationwide study. Again, the same conclusions were found--on-street bicycling is safe, and definitely safer than cycling on sidewalks, sidepaths, or off-street paths.
Here is a summary of results from a typical study:
Relative Danger Index Facility
---------------------- --------------------------------------------
(Safest) 0.41 major roads with bicycle facilities (marked
bicycle lanes)
. 0.51 signed bike routes (wide outside lanes &
signs only, no bike lanes)
. 0.66 major road without bicycle facilities
. 0.94 minor road without bicycle facilities
. 1.39 multi-use path
(Most dangerous) 16.34 sidewalk
"Relative Danger Index" basically tells you which facility is more or less dangerous per mile ridden.
- - - -
Three conclusions stand out:
1. Adding bike facilities increases safety. Probably most of
the safety increase comes from the increased road width, not
necessarily the little white stripes. But regardless, safety
does increase with BikeKC-style facilities.
2. Off-road paths are more dangerous than any on-street facilities.
3. Major streets can actually be safer than minor streets for
bicyclists.
None of these facts make any sense to the motorist, because the motorist believes, falsely, that the main danger to bicylists riding on the street is being hit from the rear.
In fact, being hit from the rear accounts for only about 5% of bicycle/motor-vehicle collisions and only about 0.3% of all daylight bicycle accidents in urban areas (remember that less than 50% of bicycle accidents involve motor vehicles, and these other types of accidents can be VERY dangerous).
In practical terms, this means that there are 8 or more accident types that are more common and more dangerous to bicyclists than the rear overtaking collision. All of these involve motorists that are to the front or sides of the bicycle.
Riding on the sidewalk, for instance, might decrease rear overtaking accidents but GREATLY increases all the other kinds (accidents at driveways, intersections, etc.).
By the same token, driving on "minor streets" might (or might not) decrease rear-overtaking accidents, but with poor sight-lines, more driveways, and intersections that are not controlled as well, it increases the other (more common) types of accidents.
- - - -
The statistics above come from William E. Moritz, �Adult Bicyclists in the U.S.�, Transportation Research Board, 1998. See http://www.bicyclinglife.com/Library/Moritz2.htm
Other studies, all of which come to the same essential conclusions:
Kaplan, Jerrold, Characteristics of the Regular Adult Bicycle User. FHWA,
1975. (NTIS Document PB 258-399)
Moritz, William E., Regular Adult Bicyclists in Washington State. ASCE
Transportation Congress, San Diego. 1995.
Kenneth Cross; Identifying Critical Behavior Leading to Collisions Between Bicycles and Motor Vehicles; Office of Traffic Safety, State of California; June, 1974
Cross, Kenneth D. & Gary Fisher; A Study of Bicycle/Motor-Vehicle Accidents: Identification of Problem Types and Countermeasure Approaches; National Highway Traffic Safety Administration, Sept. 1977
posted by Brent Hugh at
Sunday, August 25, 2002 |
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