Transcript Centre for Accident Research & Road Safety - Queensland Bicycling injuries and perceived risk Simon Washington, Narelle Haworth & Amy Schramm [email protected]; [email protected]; [email protected] INTRODUCTION METHODS Government.

Centre for Accident Research &
Road Safety - Queensland
Bicycling injuries and perceived risk
Simon Washington, Narelle Haworth & Amy Schramm
[email protected]; [email protected]; [email protected]
INTRODUCTION
METHODS
Government 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.
A 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.
Variables Used in Analysis: Self-reported Bicyclist Behaviour, Injuries and Exposure
Variable
Mnemonic
Bikinhous
Mostoftbike
Replcost
Cyclskills
Description of variable and response categories
How many bicycles in working order are kept at your household?
{0 to 9 as counts, 10 indicating 10 or more)}
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}
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, $10013000}{7.00,$3001-5000}{8.00, $5001-10000}{9.00, More than $10000}{10.00, Don't know}
How would you describe your cycling skills?
{1.00, Basic }{2, Competent}{3.00, Highly skilled}{4.00, Other}
Seemingly Unrelated Regression: Simultaneous Linear Regressions of Self-Reported
Injury Rates and Perceived Risk
Equation
Observations
Parameters
RMSE
R-square
NCInjRate
CInjRate
RiskPerc
1884
1884
1884
7
7
7
.03684
.06395
.94589
0.0666
0.1207
0.0461
Non-crash Injury Rate
Coefficient
Std Error
Z
P>|z|
Daysride
Urbankm
Replcost
avgspd_1
lowspd_3
propfrntlit_1
Constant
-.0021543
-.0000278
-.00225
-.0051683
-.0031062
-.0088783
.0453017
.0005738
.0000106
.0006191
.0024666
.0012124
.0027524
.004375
-3.75
-2.61
-3.63
-2.10
-2.56
-3.23
10.35
<0.001
0.009
<0.001
0.036
0.010
0.001
<0.001
Crash Injury Rate
Coefficient
Std Error
Z
P>|z|
-.00131
-.0000281
-.0014215
-.0049857
-.0030933
-.0089234
.0301381
.0005827
.0000109
.0006296
.0024651
.0012132
.002755
.0042063
-2.25
-2.58
-2.26
-2.02
-2.55
-3.24
7.16
0.025
0.010
0.024
0.043
0.011
0.001
<0.001
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?-
Daysride
Urbankm
Replcost
propbrtclth_1
prophelmet_5
injloc_7
Constant
Urbankm
What is the distance (in kilometres) you ride in an average week in urban areas?-
Perceived risk
Coefficient
Std Error
Z
P>|z|
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
-.0033527
-.0000531
-.002284
.0130385
-.0501007
.0227013
.1021912
-.0033527
.0010193
.0000191
.0010984
.0037515
.0098606
.0027494
.0121517
.0010193
-3.29
-2.78
-2.08
3.48
-5.08
8.26
8.41
-3.29
0.001
0.005
0.038
0.001
<0.001
<0.001
<0.001
0.001
Avgspeed
What 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}
Daysride
Propbkpth
motiv_1
grpride_1
highspd_2
prophelmet_5
propfrntlit _5
constant
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
Hosptreat
Do you ride at night (after dusk or before dawn)?- {1 = yes, 0 = no}
When 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}
When 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}
When 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}
Where 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}
Where 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}
Where 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}
Where 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}
When 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}
When 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}
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}
How 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}
How 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}
How 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}
Calculated total number of injury events {crash plus non-crash injuries}
{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}
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}
Lowspd
Midspd
Highspd
Propbrtclth
Propflrclth
Proprflclth
Prophelmet
Propfrntlit
Proprearlit
Cyclperisk
Riskavoid
Noncrashinj
Crashinj
Injevents
Injlocation
Chisquare
157.98
312.00
90.89
P-value
<0.0001
<0.0001
<0.0001
RESULTS
Increasing 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.
DISCUSSION
Perceived 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.
Acknowledgements
This research was funded by a Queensland Health Trauma Research Grant
The Centre for Accident Research and Road Safety - Queensland