bicycling injuries and perceived risk simon washington, narelle haworth & amy schramm the centre...
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Bicycling injuries and perceived riskSimon Washington, Narelle Haworth & Amy Schramm
The Centre for Accident Research and Road Safety - Queensland
AcknowledgementsThis research was funded by a Queensland Health Trauma Research Grant
Centre for Accident Research & Road Safety - Queensland
INTRODUCTIONGovernment promotion of active transport has renewed interest in cycling safety. Research has shown that bicyclists are up to 20 times more likely to be involved in serious injury crashes than drivers. On-road cycling injuries are under-reported in police data, and many non-serious injuries are not recorded in any official database. This study aims to explore the relationships between rider characteristics and environmental factors that influence per kilometre risk of bicycle-related crash and non-crash injuries.
RESULTSIncreasing exposure and having more expensive bicycles were shown to reduce the risk per km of crash and non-crash injury rates, and to reduce perceived risk. Never wearing bright coloured clothing related to increased crash risk, use of fluorescent and reflective clothing had no effect on crash risk. Riding in low-speed environments, never using a front light, and riding in low-speed environments were associated with reduced non-crash injury risk. Perceived risk was influenced by exposure, use of conspicuity aids and helmets, riding for utilitarian reasons, and group-riding behaviours.
DISCUSSIONPerceived risk does not appear to influence injury rates and injury rates do not appear to influence the perceived risk of cycling. Riders who perceive cycling to be risky tend not to be commuters, do not engage in group riding and always wear helmets. Not all measures of conspicuity were associated with risk, with rear lights found to have no relationship to injury. The risks of experiencing a crash or non-crash injury were similar, therefore injury prevention strategies should expand their scope to include other factors such as the importance of bicycle set-up.
METHODSA survey of 2,532 Queensland adults who had ridden at least once in the past year was conducted from October 2009 to March 2010, with most responses received online (99.3%). Riders were asked where they rode (footpath, bike path, road etc.), average travel speed, purpose of riding, type of bike ridden, how far and how often they rode in. Measures of rider experience, skill, safety perceptions, safety behaviours, crash involvement and demographic characteristics were also collected.
Seemingly Unrelated Regression: Simultaneous Linear Regressions of Self-Reported Injury Rates and Perceived Risk
Equation Observations Parameters RMSE R-squareChi-
square P-value
NCInjRate 1884 7 .03684 0.0666 157.98 <0.0001CInjRate 1884 7 .06395 0.1207 312.00 <0.0001RiskPerc 1884 7 .94589 0.0461 90.89 <0.0001
Non-crash Injury Rate Coefficient Std Error Z P>|z|
Daysride -.0021543 .0005738 -3.75 <0.001
Urbankm -.0000278 .0000106 -2.61 0.009Replcost -.00225 .0006191 -3.63 <0.001avgspd_1 -.0051683 .0024666 -2.10 0.036
lowspd_3 -.0031062 .0012124 -2.56 0.010
propfrntlit_1 -.0088783 .0027524 -3.23 0.001Constant .0453017 .004375 10.35 <0.001
Crash Injury Rate Coefficient Std Error Z P>|z|
Daysride -.00131 .0005827 -2.25 0.025Urbankm -.0000281 .0000109 -2.58 0.010
Replcost -.0014215 .0006296 -2.26 0.024
propbrtclth_1 -.0049857 .0024651 -2.02 0.043
prophelmet_5 -.0030933 .0012132 -2.55 0.011
injloc_7 -.0089234 .002755 -3.24 0.001Constant .0301381 .0042063 7.16 <0.001
Perceived risk Coefficient Std Error Z P>|z|
Daysride -.0033527 .0010193 -3.29 0.001
Propbkpth -.0000531 .0000191 -2.78 0.005motiv_1 -.002284 .0010984 -2.08 0.038
grpride_1 .0130385 .0037515 3.48 0.001highspd_2 -.0501007 .0098606 -5.08 <0.001
prophelmet_5 .0227013 .0027494 8.26 <0.001propfrntlit _5 .1021912 .0121517 8.41 <0.001
constant -.0033527 .0010193 -3.29 0.001
Variables Used in Analysis: Self-reported Bicyclist Behaviour, Injuries and Exposure
Variable Mnemonic
Description of variable and response categories
Bikinhous How many bicycles in working order are kept at your household? {0 to 9 as counts, 10 indicating 10 or more)}
Mostoftbike Bicycle ridden most often {0.00, no answer}{1.00, Childs}{2.00, Hybrid}{3.00,Noncomp Road}{4.00, Comp road}{5.00, Off Road}{6.00, Other}
Replcost
How much would it cost to replace the bicycle (frame and bicycle parts, excluding accessories) you ride most often with a similar new bicycle?{1.00, Less than $150}{2.00, $150-300}{3.00, $301-500}{4.00, $501-800}{5.00, $801-1000}{6.00, $1001-3000}{7.00,$3001-5000}{8.00, $5001-10000}{9.00, More than $10000}{10.00, Don't know}
Cyclskills How would you describe your cycling skills?{1.00, Basic }{2, Competent}{3.00, Highly skilled}{4.00, Other}
Exprider New (riding in 2008 and/or 2009), Experienced (all 5 years), and Other{1.00, new rider}{2.00, experienced rider}{3.00, other}
Daysride How many days on average do you ride a bicycle in a week?{0.00, 0}{1.00, 1}{2.00,2}{3.00, 3}{4.00, 4}{5.00, 5}{6.00,6}{7.00, 7}
Hoursride What is the time (in hours) you spend riding in an average week?-
Distride What is the distance (in kilometres) you ride in an average week?-
Footpthkm What is the distance (in kilometres) you ride in an average week on footpaths?-
Bikepthkm What is the distance (in kilometres) you ride in an average week on bike paths?-
Urbankm What is the distance (in kilometres) you ride in an average week in urban areas?-
Ruralkm What is the distance (in kilometres) you ride in an average week in rural areas?-
Propftpth Calculated proportion of kilometres ridden on the footpath
Propbkpth Calculated proportion of kilometres ridden on the bicycle path
Propur Calculated proportion of kilometres ridden on the urban roads
Proprural Calculated proportion of kilometres ridden on the rural roads
Propofrd Calculated proportion of kilometres ridden on the off-road
AvgspeedWhat is your average travel speed (not including waiting for traffic or rest stops) when cycling?{1.00, Less than 16km/h}[2.00, 16-18.9 km/h}{3.00, 19-21.9 km/h}{4.00, 22-24.9km/h}{5.00, 25-32km/h}{6.00, more than 32km/h}{7.00, Don't know}
Motiv Primary motivation for riding {Utilitarian =1, Social =2, Health =3}
Grprides Do you participate in group (3 or more cyclists) rides?{1 = yes, 0 = no}
Nitrides Do you ride at night (after dusk or before dawn)?- {1 = yes, 0 = no}
LowspdWhen riding on the road, how often are you on roads with the following speed ...- 40-60km/h{1.00, Never}{2.00, Sometimes}{3.00, Mostly}
MidspdWhen riding on the road, how often are you on roads with the following speed ...- 70-80km/h{1.00, Never}{2.00, Sometimes}{3.00, Mostly}
HighspdWhen riding on the road, how often are you on roads with the following speed ...- 90-110km/h{1.00, Never}{2.00, Sometimes}{3.00, Mostly}
PropbrtclthWhere you ride most often, what proportion of the time do you wear bright coloured clothing or accessories?{1.00, Never}{2.00,Rarely}{3.00, Sometimes}{4.00, Often}{5.00, Always, Almost always}
PropflrclthWhere you ride most often, what proportion of the time do you wear fluorescent clothing or accessories?{1.00, Never}{2.00,Rarely}{3.00, Sometimes}{4.00, Often}{5.00, Always, Almost always}
ProprflclthWhere you ride most often, what proportion of the time do you wear reflective clothing or accessories?{1.00, Never}{2.00,Rarely}{3.00, Sometimes}{4.00, Often}{5.00, Always, Almost always}
ProphelmetWhere you ride most often, what proportion of the time do you wear a helmet? {1.00, Never}{2.00,Rarely}{3.00, Sometimes}{4.00, Often}{5.00, Always}
PropfrntlitWhen riding in reduced visibility conditions (darkness, fog, rain, etc.) where you ride most often, what proportion of time do you use a front light (steady or flashing){1.00, Never}{2.00,Rarely}{3.00, Sometimes}{4.00, Often}{5.00, Always}{6.00, Not applicable}
ProprearlitWhen riding in reduced visibility conditions (darkness, fog, rain, etc.) where you ride most often, what proportion of time do you use a rear light (steady or flashing){1.00, Never}{2.00,Rarely}{3.00, Sometimes}{4.00, Often}{5.00, Always}{6.00, Not applicable}
Cyclperisk
Which statement best describes your opinion about the safety of cycling as a means of transport?{1.00, Cycling is much safer than driving a car}{2.00, Cycling is somewhat safer than driving a car}{3.00, Cycling is about as safe as driving a car}{4.00, Cycling is somewhat less safe than driving a car}{5.00, Cycling is much less safe than driving a car}
RiskavoidHow would you describe your attitude to risk when cycling? {1.00, I try to avoid risk}{2.00, I don't think about risk}{3.00, I seek out risk}
NoncrashinjHow many times in the past 2 years have you been injured while cycling without crashing (eg. muscle strain, foreign object in eye)? This does not include falling off the bicycle or colliding with something/someone. {count of injuries}
CrashinjHow many times in the past 2 years have you been injured as a result of a crash (eg. being hit by a car, falling off your bicycle)? {count of injuries}
Injevents Calculated total number of injury events {crash plus non-crash injuries}
Injlocation{0, none}{1, Footpath}{2, bike path}{3, urban road with on-road bike facility}{4, urban road without on-road bike facility}{5, rural road}{6, off-road/trail}{7, track (velodrome/bmx)}{8, skate park}{9, urban/street scapes}{10, other}{11, home}{12, N/A}
Hosptreat Were you treated at hospital as a result of the injury? {1 = yes, 0 = no}
hospadm Were you admitted to a hospital as a result of the injury? {1 = yes, 0 = no}