Conspicuity issues for
motorcycles and bicycles
Narelle Haworth
Presentation to National Road Safety Forum, Tasmania 2013
Outline
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Active safety for two wheelers
Conspicuity concepts and measurement
Themes and methods in conspicuity research
Use of conspicuity aids
Effectiveness of conspicuity aids
Issues for the future
Active safety for two-wheelers
• PTWs
– traditionally, most focus in crash avoidance on driver training, not
vehicle safety
– development and evaluation of improved braking systems for
PTWs
– recent work on performance and acceptability of Advanced Rider
Assistance Systems
• Bicycles
– little work in improving active safety of vehicle
– recognition of benefits for VRUs of some active safety sytems for
motor vehicles (ISA, automatic braking, blind spot reduction for
HVs, V2V, V2I) (Steriu, 2012)
Major TW safety issues
• 80% of on-road bicycle and 58% of motorcycle rider
fatalities in Australia involve motor vehicles (DIT, 2012)
• Plus at least 22% of hospital admissions for on-road
bicycle crashes (Henley and Harrison, 2012)
• Car driver mostly at fault in TW crashes
• Evidence of looked but failed to see (LBFS)
Conspicuity
• The object’s ability to attract visual attention
• Perceptual or sensory conspicuity
– Relates to physical characteristics such as colour,
luminance, angular size, position in field of view,
angular velocity, loudness
• Cognitive conspicuity
– Expectancy
– Relates to frequency of stimulus, position, velocity,
personal interest and experience
Importance of cognitive conspicuity
• Examination of bicycle-car crashes found that bicyclists
aren’t where drivers look (Rasanen and Summala, 1998)
– This questions value of both sensory conspicuity improvements
and passing distance requirements
• Car drivers with motorcycling experience (dual drivers)
less likely to be involved in motorcycle crashes or be at
fault (Brooks & Guppy, 1990; Magazzu et al., 2006)
• Dual drivers know where to look for motorcycles
– Roge et al. (2012) dual drivers detected mcycs in rear vision at
greater distance in simulator
• Crundall et al. (2008) car drivers with motorcycling
experience held more positive beliefs about
motorcyclists than other car drivers
Themes of conspicuity research
• Benefits of motorcycle daytime lights
• Effects of DRL for other vehicles on VRU
detectability
• Patterns of use of conspicuity aids and factors
predicting use
• Factors underlying looked but failed to see
• General studies of factors contributing to mcyc
and bicycle crashes with conspicuity as one
factor
Discussion of methods used in
conspicuity research
• Laboratory experiments
– Priming “respond when you see a motorcycle” or too many TWs
– Detection versus recognition and reaction
– Often static images or lack of competing tasks
• Simulator
• Surveys of rider attitudes and behaviours
– High distances ridden, adults, road bikes, low severity crashes
• Observational studies
• Crash data and indepth analyses
– Sometimes inappropriate comparisons, other confounding
factors
Reported use of conspicuity aids by
cyclists
• Always use rear light in dark/low-light conditions
– 92% NZ, 90% Qld
• Always use front light in dark/low-light conditions
– 87% NZ, 84% Qld
• Wear fluoro clothing/accessories
– 30% always NZ, 14% always/almost always Qld
– higher for females NZ
• Wear bright coloured clothing/accessories
– 43% always/almost always Qld
• Wear reflective clothing/accessories
– 21% always/almost always Qld
(NZ: Thornley et al., 2011, Qld: unpublished CARRS-Q data)
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CASR cyclist observations
• Adelaide CBD commuter cyclists (Raftery & Grigo, 2013)
• 38% of cyclists had high frontal conspicuity; 8% wore
high visibility vests
• 18% of cyclists had high rear conspicuity
• 57% of cyclists with high frontal conspicuity had
obscured rear conspicuity, mainly backpacks (particularly
males)
• High visibility vest more common if wearing non-cycling
clothing and aged 30-59 (cf 20-29)
Effectiveness of conspicuity aids
• Taupo Bicycle Study (Thornley et al., 2011)
– riders who always wore fluorescent colours had 8x
fewer days off work from bicycle crash injury in last
year (cf never wear)
– controlled for age group, gender, average cycling
speed, years of experience, bunch riding, distance
ridden per year
• Motorcycle case-control study (Wells et al., 2004)
– high visibility clothing associated with 37% lower
injury risk
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Effectiveness of conspicuity aids
• Cochrane Review (Kwan & Mapstone, 2009)
• Daytime:
– fluorescent yellow, red and orange improved detection and
recognition
– yellow was best non-fluoro
• Night-time:
– lamps and flashing lights
– retroreflective material in red and yellow
• Other factors: road condition, contrast, weather, street
lighting, background clutter, vehicle roadworthiness
• Survey: Riders and pedestrians over-estimate their own
visibility (Wood et al., 2009)
• Promising approaches focus on incorporating movement into
lighting
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Biomotion (biological motion)
• Visual sensitivity to patterns of human motion
can be used to improve the conspicuity of
bicyclists at night
• Wood et al. (2012) on-road experiment showed
– Knee and ankle reflectors increased drivers’ detection
distances over reflective vest alone or black clothing
alone
– Knee and ankle reflectors compensated for poorer
detection by older drivers
– Static or flashing bicycle light did not enhance
detection
Phi-phenomenon
• Illusion of movement (and greater size) when two
flashing lights (Gershon & Shinar, 2013)
• Motorcycles detected more often and more quickly with
ABLS cf bright colours, especially in clutter and dusk
Issues for the future
• Growth in both motorcycle and bicycle use
– Enough to change cognitive conspicuity??
• Electric bicycles may not have the speed
profiles expected for bicycles
• More cars with DRL?
• Acceptability of conspicuity enhancements
• Will car-based systems for detecting VRUs
solve the problem?
– Issue of age of vehicle fleet
Take-home messages
• Bright colours and lights are good but not
enough
• Moving lights may be more effective than
stationary
• Driver experience is an important
determinant of whether TWs are seen
Questions?
n.haworth@qut.edu.au
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References (1)
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Brooks, P. & Guppy, A. (1990). Driver Awareness and Motorcycle Accidents.
Proceedings of the International Motorcycle Safety Conference, 2(10), 27–56.
Crundall , D., Bibby, P., Clarke, D., Ward, P., & Bartle C. (2008). Car drivers’ attitudes
towards motorcyclists: A survey. Accident Analysis and Prevention , 40, 983–993
DIT. (2012). Australian road deaths database.
http://www.bitre.gov.au/statistics/safety/fatal road crash database.aspx
Gershon, P. & Shinar, D. (2013). Increasing motorcycles attention and search
conspicuity by using Alternating-Blinking Lights System (ABLS). Accident Analysis
and Prevention , 50, 801-810.
Goldenbeld, C., Houtenbos, M. & Ehlers, E. (2010). The use of portable media
players and mobile phones while cycling; Results of a large-scale internet survey (R2010-5). SWOV: Leidschendam, The Netherlands. (Dutch with English abstract)
Henley, G., Harrison, J.E. (2012). Trends in Serious Injury Due to Land Transport
Accidents, Australia 2008–09. INJCAT 143. Injury Research and Statistics Series no.
67. Australian Institute of Health and Welfare, Canberra.
References (2)
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Kwan, I. & Mapstone, J. (2004). Visibility aids for pedestrians and cyclists: a
systematic review of randomised controlled trials. Accident Analysis and Prevention,
36(3), 305–312.
Magazzu, D., Comelli, M. & Marinoni, A. (2006). Are car drivers holding a motorcycle
licence less responsible for motorcycle–car crash occurrence? A non-parametric
approach. Accident Analysis and Prevention, 38, 365–370.
Raftery, S.J. & Grigo, J.A.L. (2013). The conspicuity of South Australian cyclists:
implications for safety (CASR113).
Rasanen, M. & Summala, H. (1998). Attention and expectation problems in bicycle–
car collisions: an in-depth study. Accident Analysis and Prevention, 30(5), 657–666.
Steriu, M., 2012. Raising the Bar – Review of Cycling Safety Policies in the European
Union. European Transport Safety Council, Brussels.
References (3)
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Thornley, S.J., Woodward, A., Langley, J.D., Ameratunga, S.N., Rodgers, A. (2008).
Conspicuity and bicycle crashes: preliminary findings of the Taupo Bicycle Study.
Injury Prevention, 14(1), 11–18.
Wells, S., Mullin, B., Norton, R., Langley, J., Connor, J., Lay-Yee, R. (2004).
Motorcycle rider conspicuity and crash related injury: case-control study. British
Medical Journal, 328, 828–857.
Wood, J.M., Lacherez, P.F., Marszalek, R.P., King, M.J. (2009). Drivers’ and cyclists’
experiences of sharing the road: incidents, attitudes and perceptions of visibility.
Accident Analysis and Prevention, 41(4), 772–776.
Wood, J.M., Tyrrell, R.A., Marszalek, R., Lacherez, P., Carberry, T., Chu, B.S. (2012).
Using reflective clothing to enhance the conspicuity of bicyclists at night. Accident
Analysis and Prevention, 45, 726–730.
Yuan, W. (2000). The effectiveness of the ‘ride-bright’ legislation for motorcycles in
Singapore. Accident Analysis and Prevention, 32(4), 559–563.