Abstract
Traffic records for all bicyclist fatalities occurring in Arizona during the year 2009 were categorized and listed according to manner of collision and assignment of fault. Primary results are that 11 of 25 fatalities (44%) were determined to be the fault of the cyclist; while 14 of 25 (56%) were the fault of a motor vehicle driver. The most common manner of collision is when a driver strikes a cyclist from behind.
Full Report
The full report is available in pdf format:
Manner and Fault in Bicyclist Traffic Fatalities: Arizona 2009
Supporting data: 2009CyclistFatals.xls
Comments or questions may be left here, or contact me.
Advertisement
This conference paper may be of interest: Schramm, Amy J. and Rakotonirainy, Andry and Haworth, Narelle L. (2008) How much does disregard of road rules contribute to bicycle-vehicle collisions? full text .pdf.
“The analysis would suggest that it is usually driver behaviour that contributes to bicycle vehicle collisions, with the motor vehicle being the at fault unit in nearly two thirds of reported crashes. This trend is even more noticeable in bicycle-vehicle collisions where the cyclist is of driving age. Traffic violations were reported in over two thirds of bicycle-vehicle collisions. In crashes where traffic violations were found to have occurred, vehicles were more likely to have broken the road rules. This is in contrast to the popularly held opinion that cyclists’ failure to adhere to road rules results in crashes”
I would like to respond to any/all criticisms or questions…
Here is one from a thread at rec.bicycles.tech
> P.S. And while data collection on this is poor, there are some strong
> indications that a large percentage of the “hit from behind” cyclists
> are riding in the dark without lights or reflectors.
I think the data, poor though it may be, shows that is not at all the case:
There were 10 hit-from-behind cases.
Only 4 were in darkness. I tend to believe that all of these victims were meeting their lighting requirement/duty (to have a rear reflector or light). In at least two of the cases the police specifically said to the media words to the effect of “the bicyclist was doing everything right”, or something.
By the way; all four were hit-and-run drivers.
Additionally, three of the four generated indictments for manslaughter (and IIRC all 3 resulted in conviction of either manslaughter or neg hom); I am told authoritatively that to prove any homicide charge here the prosecution must show the collision was the fault of the defendant, and not simply that the defendant was DUI.
The fourth driver ended up getting convicted of “simple” leaving-the-scene.
Other anecdotal evidence is that several (3 by my count) were somewhat hard-core roadies doing night training during our (Phoenix) hot weather months, and not, say, homeless transients just out rolling around. (I don’t say that to sound cold. every life is sacred; but all things being equal some groups of cyclists are more likely than others to have a reflector or light).
The other 6 were in the light. One was listed as dawn and that guy specifically had a reflector (and large/slow vehicle triangle). the dusk victim’s driver complained of sun glare.
This paper has a rather long title –
White Papers for: “Toward Zero Deaths: A National Strategy on Highway Safety” —White Paper No. 5— Safer Vulnerable Road Users: Pedestrians, Bicyclists, Motorcyclists, and Older Users
http://safety.transportation.org/doc/web5%20Vulnerable%20Users%20White%20Paper.pdf
It is intersting to see if their cited data aligns with the 25 fatals studied in Arizona; for example, helmet usage “the IIHS bicycle fact sheet indicates that 91 percent of the bicyclists killed in 2008 reportedly were not wearing helmets”. In the Arizona sample, 24% were wearing helmets, and 40% were known to be not wearing one. The rest were unknown.
Another example was darkness — “The Florida study of fatal crashes showed approximately 60 percent of the fatal bicyclist crashes occurring in non-daylight conditions, and that more than 45 percent of the bicycles involved in nighttime crashes had no lighting (Spainhour et al, 2005).”
In the Arizona data 52% were non-daylight, and I am working on trying to find a number for nighttime w/no lighting