Vision Science and Road Safety
Submitting InstitutionRoyal Holloway, University of London
Unit of AssessmentPsychology, Psychiatry and Neuroscience
Summary Impact TypeSocietal
Research Subject Area(s)
Medical and Health Sciences: Public Health and Health Services
Psychology and Cognitive Sciences: Psychology
Summary of the impact
The World Health Organization cites road traffic accidents as one of the
world's leading health concerns. Research in the Department of Psychology
at Royal Holloway, University of London has investigated the relationship
between fundamental aspects of human visual processing across the lifespan
and the scenarios in which road accidents are most likely to occur. This
research has been at the heart of a national campaign to lower urban speed
limits, particularly where child pedestrians are present. It has also led
to improved driver safety in commercial organisations, and has contributed
to the commercial design of driver assistance systems.
This research has been led by Professor John Wann, who joined the
Psychology Department at Royal Holloway, University of London in 2006. He
has been supported by a team of doctoral and postdoctoral researchers
including Dr. J. Billington (now U. Leeds), Dr. D. Poulter (now U.
Greenwich), Dr. R. De Oliveira (now South Bank U.), Dr. R. Wilkie (now U.
Leeds), Dr. D. Field (now U. Reading), Dr. C. Purcell (now U. Newport),
and Dr. M. Gould.
Wann's research has investigated the neural processes underpinning
collision detection  and the limits of human visual processing in
relation to critical road traffic events. Specifically, this research has
identified thresholds for the detection of approaching vehicles (including
motorcycles), and for the discrimination of speed of vehicle approach.
Further, it has done so for three groups that figure disproportionately in
road traffic accidents: typically-developing primary-school children ,
primary-school children with perceptual-motor disabilities , and
drivers over the age of 75 .
Based on detection and discrimination thresholds for the populations
identified above, this research has established that:
(a) children's judgments of vehicle approach become unreliable for
vehicle speeds above 25mph, thus emphasizing the need to reduce speed
limits in areas in which children are present ;
(b) older adults exhibit poor speed discrimination , rendering them
liable to error, particularly at A-road intersections where traffic
approach speeds may vary between 30-60mph (which older drivers fail to
discriminate, but which reduce their available pull-out time by up to
(c) errors in judging motorcycle approach increase as night falls [5, 6]
to a much greater extent than they do for cars due to the lack of
dual-headlights (that optically separate as a car approaches), but that
the error for motorcycles can be significantly reduced using a tri-light
modification that has not to date been introduced for most production
This work thus demonstrates that the perceptual acuity for judging
vehicle approach in road users is below what would be optimal given the
current range of traffic speeds. This research has further demonstrated
that children under the age of 11 years [2,3] and drivers over the age of
75 years  are likely to make errors, and that motorcyclists are
particularly vulnerable as a consequence of these errors [5,6].
This research has been published in scholarly outlets of the highest
quality including Psychological Science, Proceedings of the
Royal Society: Biological Sciences, Journal of Neuroscience
and Journal of Experimental Psychology: Human Perception &
Performance. It has also attracted over £1m in research funding in
the past 5 years from UK research councils and road safety charities.
These indices provide evidence of the quality of the underpinning
References to the research
Outputs (Researchers with * were all PDRAs or PGRs with the Wann
1. *Billington, J., *Wilkie, R.M., *Field, D.T., & Wann, J.P. (2010).
Neural processing of imminent collision in humans. Proceedings of the
Royal Society B: Biological Sciences, 1711, 1476-1481.
2. Wann, J.P., *Poulter, D.R., & *Purcell, C. (2011). Reduced
sensitivity to visual looming inflates the risk posed by speeding vehicles
when children try to cross the road. Psychological Science, 22,
3. *Purcell, C., Wann, J.P., *Wilmut, K., & *Poulter, D. (2011).
Roadside judgments in children with Developmental Co-ordination Disorder.
Research in Developmental Disabilities, 32, 1283-1292.
4. *Poulter, D.R. & Wann, J.P. (2013). Errors in motion processing
amongst older drivers may increase accident risk. Accident Analysis and
Prevention, 57, 150-156.
5. *Gould, M., *Poulter, D.R., Helman, S., Wann, J.P. (2012). Errors in
judging the approach rate of motorcycles in night time conditions and the
effect of an improved lighting configuration. Accident Analysis and
Prevention, 45, 432-437.
6. *Gould, M., *Poulter, D.R., Helman, S., Wann, J.P. (2013). Detection
of vehicle approach in the presence of additional motion and simulated
observer motion at road junctions. Journal of Experimental Psychology:
Applied, 19, 171-184.
Selected Research Funding
Wann's research has attracted £3.34m of research funding since 1993. Some
recent examples include:
2007-2010, EPSRC. Neural correlates of collision detection (PI).
2008-2011, ESRC. Perceptual judgments of children in a road crossing
situation (PI). £324,000.
2010-2011, Royal Society for the Prevention of Accidents. Errors in
perceptual judgments amongst elderly road users (Co-PI). £20,000.
2009-2012, EU FP7. Coding of Optimal Decisions for Dynamic Environments
2011-2012, ESRC (Knowledge Transfer). Enhancing driver awareness of
perceptual errors in approach speed judgments for road crossing and
decisions at junctions (PI). £89,577.
Details of the impact
This research is delivering significant and far-reaching impacts in a
number of areas concerning road safety. The main beneficiaries of this
work are (a) road users including drivers and pedestrians; (b) road safety
professionals, organisations, and charities; (c) local authorities; and
(d) commercial organisations seeking to reduce the involvement of their
drivers in road accidents.
Road Users, Road Safety Organisations and Charities, and Local
Authorities. This research has had substantial impacts across the
UK, and increasingly, around the world, because it provides a clear
rationale based upon human perceptual abilities for wider use of 20 mph
traffic zones. It has been featured in national and regional TV, radio,
and print news, and provided the lead story for BBC1's "Bang Goes the
Theory" which focused on children's road safety (March, 2013). It was also
featured in National Road Safety Week in 2010 and 2012, and in a number of
major road safety meetings organised through the campaign body Brake.
Most importantly, this research has been central to a successful UK
campaign by 20sPlenty (a national body with nearly 200 regional
campaigns), to argue for a reduction in urban speed limits, especially in
areas in which children are present. This campaign has resulted in the
adoption of default 20mph speed limits for residential streets in 40 local
authorities (including e.g. Liverpool, Portsmouth, Bristol, York,
Brighton, Bath, Newcastle, Oxford, Cambridge, Hackney) comprising nearly
10 million residents. Twelve further local authorities (including e.g.
Birmingham, Wirral, Ealing, Norwich) comprising nearly 2.5 million
residents have made a political commitment to implementing default 20mph
speed limits for residential streets. Most recently, Wann was invited to
give evidence to a transport select committee convened by North
Lincolnshire Authority which resulted in a large number of urban speed
limits being revised downwards, including the greater use of 20mph zones.
Wann's research and advice is cited extensively in the final report (http://tinyurl.com/NLincsReport).
Based on epidemiological research (1986-2006; Grundy et al., 2009, British
Medical Journal, 339, b4469) suggesting that 20mph traffic zones can
reduce road casualties by 42%, and based on Department for Transport
pedestrian casualty figures for 2011 (5,907 killed or seriously injured,
hereafter KSI), we estimate that the speed limit reductions in these
local authorities alone have the potential to prevent 496 KSI
outcomes annually, including saving 38 pedestrian lives each year.
Royal Holloway research on children's road crossing  has also been
featured by other local campaigns to highlight the importance of school
crossing patrols, and it was described in a parliamentary question to the
Under Secretary of Transport concerning the impact of budget cuts on these
patrols in Dorset (Hansard 16/3/11). This specific campaign was successful
in saving 84% of school crossing patrols in Dorset (51 out of 61 patrols).
Road Safety Professionals and Commercial Organisations. Royal
Holloway research on human perceptual abilities in relation to critical
road traffic events has also had impact through grass-roots interaction
with road safety professionals and commercial organisations. During the
period, Wann and his team have presented their research at a number of
road safety meetings in which road safety officers (RSOs) were attending
as part of their continuing professional development. This interaction has
been consolidated by RSOs, Police, and Fire Service attendees downloading
the interactive computer-based demonstrations designed at Royal Holloway
through ESRC Knowledge Transfer funding for use in local driver education
programmes. It has also led to active collaborations with the BAA Heathrow
safety team, who are responsible for over 11,000 vehicles and over 20,000
drivers operating in a 5sq mile area. Software developed at Royal Holloway
that demonstrates what our research has uncovered about drivers'
perceptual errors is now being used in BAA Heathrow's safety awareness
programme (e.g. Airside Safety Week, 2012).
Finally, as a result of his high-quality research on collision detection,
Wann was invited onto the scientific advisory committee for the QUADRA
project at Volvo Technology, which has a specific focus on modelling
driver interaction with Forward Collision Warning (FCW) and lane departure
systems. This is an active committee comprising two leading scientists
from the USA, one from Sweden, and one from the UK (Wann) who provide
human factors advice on FCW developments. The systems being piloted and
developed through advice from this committee have the potential to affect
hundreds of thousands of road users, not only those who have purchased a
Volvo vehicle, but also those who will benefit from (a) the intervention
of advanced control systems in a vehicle that might otherwise have caused
a collision and (b) similar vehicle designs by other manufacturers moving
towards the standard set by Volvo. Through this link with Wann's research
group, Volvo Technology was in turn a collaborator in an EU Network
training early career scientists in the field (EU FP7 Marie Curie
Sources to corroborate the impact
1. The campaigning group 20splenty has highlighted Wann's research in
their national campaign, which has led to the adoption of 20mph
residential limits in 40 local authorities and commitments to these
reductions in a further 12 local authorities (see http://www.20splentyforus.org.uk/press_releases.htm).
Verification Contact: 20splenty Founder & Campaign Director.
2. The impact of Wann's research on the decision by North Lincolnshire
Authority to reduce their speed limits can be found in this report http://tinyurl.com/NLincsReport.
The announcement by North Lincolnshire Authority to reduce their speed
limits is on http://tinyurl.com/NLincs
Announcemt Further verification of Wann's role can be obtained from
Policy Officer (Policy Performance and Development), NE. Lincs Authority.
3. Wann's work provided the rationale for a parliamentary question
regarding the implications of budget cuts on school crossing patrols.
Hansard 16 March, Column 131 WH: http://tinyurl.com/Hansard16March
School Crossing Patrols (Dorset) 4.49 pm: Annette Brooke (Mid Dorset and
North Poole) (LD): " Although the United Kingdom has the second lowest
road death rate in the EU, its child pedestrian death rate is worse than
in 10 other EU countries, and eight times higher than in Sweden. Research
by Royal Holloway, University of London shows that children are unable to
accurately judge the speed of vehicles travelling at more than 20 miles
per hour. The study found that children aged six to 11 suffered from speed
illusion, which means that they cannot make a reliable guess at a car's
speed if it is going at more than 20 miles per hour, unlike adults, who
accurately judge speeds of up to 50 miles per hour. Since 2003, death and
injury rates have fallen every year, but road safety groups fear that that
trend could end if school crossing patrols were axed. The Minister will be
aware that several authorities, including Dorset, propose changes in their
provision of school crossing patrols. (contind.)".
4. Wann's research has been central to media debate around the issue of
urban speed regulation http://www.bbc.co.uk/programmes/b01rmp0d Multiple media links at
5. Wann's research has featured in numerous road safety events organised by
the road safety charity Brake where road safety officers were brought into
contact with the Royal Holloway research team (e.g.
http://www.roadsafetygb.org.uk/news/2068.html). Verification contact:
Deputy Chief Executive, Brake, The Road Safety Charity.
6. Verification of the role of Wann's research in enhancing the training
provided to drivers employed by BAA Heathrow can be obtained from Airside
Safety Officer, Airside Operations, Heathrow Airport Limited.
7. Wann is a member of the QUADRA project on Modelling Active Safety
Systems at Volvo Technology: http://tinyurl.com/QuadraProject Verification contact: Project manager, AB Volvo.