Memorandum by The Royal Society for the
Prevention of Accidents (RTS 16)
ROAD TRAFFIC SPEED
People who drive or ride too fast for the prevailing
road and traffic conditions cause, or contribute to, one third
of road crashes, resulting in deaths of over 1,000 people each
year. Drivers and riders exceeding the speed limit are more likely
to be involved in crashes and their higher speed means that those
crashes are likely to cause more severe injuries, either to themselves
or to other road users.
The term inappropriate speed encompasses both
"excessive speed", when the speed limit is exceeded
(sometimes by wide margins) but also driving or riding within
the speed limit when this is too fast for the particular conditions
at the time (for example, in poor weather, poor visibility or
high pedestrian activity).
In addition to being a problem on its own, inappropriate
speed also magnifies other driver errors, such as driving too
close or driving when fatigued or distracted, multiplying the
chances of these types of driver behaviour causing an accident.
Inappropriate speed removes the driver's safety margin.
Higher Speeds Cause More Accidents
Higher speeds mean that drivers have less time
to identify and react to what is happening around them, and it
takes longer for the vehicle to stop.
Speed is a contributory factor in about one
third of all road collisions. This means that in the year 2000,
around 72,000 reported road accidents were due at least in part
to someone driving or riding too fast. These accidents caused:
the deaths of about 1,100 people;
serious injuries to about 12,700
slight injuries to about 900,000
If average speeds reduced by 1 mph, the accident
rate would fall by 5 per cent. This varies slightly according
to road type, so that a 1 mph reduction in average speed would
reduce accident frequency by about:
6 per cent on urban main roads and residential
roads with low average speeds.
4 per cent on medium speed urban roads and lower
speed rural main roads.
3 per cent on the higher speed urban roads and
rural single carriageway main roads.
If an individual drives more than 10-15 per
cent above the average speed of the traffic around them, they
are much more likely to be involved in an accident.
Drivers who speed are more likely to be involved
in collisions. They are also more likely to commit other driving
violations, such as red-light running and driving too close.
Higher Speeds Cause More Serious Injuries
Impacts at higher speeds are more severe than
at lower speeds, and so they lead to more serious injuries to
those involved. At 35 mph a driver is twice as likely to kill
someone as they are at 30 mph.
The probability of serious injury to a person
wearing a seat belt in a front seat at an impact speed of 30 mph
is three times greater than at 20 mph. At 40 mph it is over five
In collisions involving pedestrians and cars
or car-derived vans, 85 per cent of fatalities occurred at impact
speeds below 40 mph, 45 per cent occurred at less than 30 mph
and 5 per cent at speeds below 20 mph.
About 40 per cent of pedestrians who are stuck
at speeds below 20 mph sustain non-minor injuries. At speeds up
to 30 mph 90 per cent of pedestrians suffer non-minor injuries.
Pedestrians hit at speeds below 30 mph receive mainly survivable
injuries, but this changes to mainly fatal injuries at speeds
of between about 30 and 40 mph.
Hit by a car at 40 mph, nine out of ten pedestrians
will be killed.
Hit by a car at 30 mph, about half of pedestrians
will be killed.
Hit by a car at 20 mph, nine out of ten pedestrians
What is the Extent of Speeding?
The DTLR 2001 Speed Survey
More than half of all cars on motorways
and dual carriageways exceed the speed limit.
66 per cent of cars exceed the 30
mph limit in urban areas.
on 40 mph roads, 25 per cent of drivers'
Motorcyclists are the most likely
to be speeding on 40 mph urban roads.
On urban 30 mph roads, 54 per cent
of two-axle LGVs exceed the speed limit.
Most drivers will admit to speeding sometimes,
but surveys29, ,
have identified those groups who are most likely to do so:
car drivers from high-income households;
high-mileage drivers of newer, large
drivers who drive as part of their
Drivers often justify speeding on the basis
that they are "ordinary, safe speeding drivers" and
that speed limits are unrealistic. A survey by the AA Foundation
for Road Safety Research29 concluded that "speeding is not
seen as a crime","serious speeding is accepted
as dangerous, moderate speeding is not". The report also
highlighted that most drivers believe that it is the "boy
racer" and "company car driver" that are the problem
rather than themselves.
How Can Speed Related Accidents be Reduced?
Education is absolutely vital in trying to change
attitudes towards speeding. Those who drink and drive are seen
as behaving in a dangerous, anti-social and selfish manner with
little regard for the safety of other people. However, those who
speed are not regarded by the public or the media in this way
(unless they grossly exceed the speed limit). Therefore, it is
essential that the dangers caused by driving at inappropriate
speeds are clearly explained and demonstrated (in the way that
has been done for drink-driving) to work towards a general public
acceptance and ownership of the problem of illegal and inappropriate
It will be far easier to persuade people to
drive at safer speeds if they understand and accept that driving
too fast significantly increases the chances of being involved
in an accident, and significantly increases the chances of that
accident being serious or fatal.
Government publicity campaigns have highlighted
the dangers of driving too fast for many years, and should continue
to do so, with the support of all the other agencies and organisations
involved in promoting road safety. The Government's Think Campaign
and the Scottish Executive's "Foolsspeed" campaign are
strongly supported by RoSPA.
Unfortunately, road safety education and publicity
are often undermined in the mass media. Motor manufacturers, and
their advertising companies, continue to emphasise the speed and
power of their vehicles. Television motoring programmes continue
to promote the thrill of speed, placing undue emphasis on performance
at speed, often showing cars being raced (albeit not on the public
highway). Television dramas often show characters driving at speed
when speeding is not essential to the plot or the characterisation.
Motor manufacturers, national press, TV and
advertisers should not glamorise speed as exciting and exhilarating
nor as "normal" behaviour. The Advertising Standards
Authority has taken action on a number of occasions against car
advertisements that promote speed, and this is very welcome. The
ASA and other broadcast regulatory bodies could usefully review
and strengthen their guidance in this respect.
Speeding is a symptom of a more general poor
attitude towards driving. One of the weaknesses of the UK's driver
licensing system is that once the driving test has been passed,
the driver is licensed, virtually for life, with no requirement
and very little incentive to develop his/her driving skills any
further. Drivers can voluntarily take further training, such as
Pass Plus or courses offered by driver training providers such
as RoSPA, but there is little incentive for individual drivers
to do so. Only 3 per cent of drivers take any further driving
instruction after passing their test33. Therefore, there is a
need to develop new ways of encouraging drivers to continue to
develop their driving skills after the test.
Research has shown that drivers can be trained
in hazard perception skills, which will reduce their accident
risk. The Hazard Perception Test to be introduced during 2002
is probably the most significant change to the Driving Test for
decades and is warmly welcomed by RoSPA.
Graduated Licensing Systems offer opportunities
to provide phased driving experience for new drivers during the
period when they are most at risk of being involved in an accident,
and of reducing their exposure to the factors that are most dangerous
to them (including speed, alcohol, night driving and carrying
passengers). Systems vary across the world, and it is not clear
what form would be most feasible and effective in Britain. There
are already elements in place, such as the New Drivers Act, and
other elements (Log Books and Pass Plus) which could form part
of such a system. However, research is needed to assess the feasibility
and benefit of graduated licensing in Britain, and its optimal
Driver improvement courses are proving effective
in reducing the likelihood of re-offending,
and more recently Speed Awareness courses are being developed
by Local Authorities and Police Forces. If evaluation shows that
these courses reduce the likelihood of speeding offenders speeding
again, consideration should be given to developing a national
`speed offender' driver course in a similar way to the driver
improvement schemes that are now available nationally.
Drivers' choice of speed is partly dependent
on the characteristics of the road on which they are driving.
Therefore, it is important that road design clearly gives drivers
the right messages about the maximum safe speed. It is important
that speed limits are appropriate for the nature of the road on
which they are posted, otherwise drivers are less likely to respect
them and it may reinforce the argument used by some motorists
that they are unfairly penalised. The government's review of road
hierarchy will hopefully provide new guidance on setting appropriate
speed limits, so that motorists do not feel that the limits they
are asked to obey are unrealistic. This should be completed as
soon as possible.
Safer roads benefit all road users, but especially
those who are most vulnerable: pedestrians, cyclists, motorcyclists,
children and the elderly.
Speed management is central to road safety.
A number of local authorities have already introduced comprehensive
speed management strategies that have been successful in reducing
casualties and average speeds. Good practice in this field should
be highlighted and disseminated.
The "IHT Urban Safety Management Guidelines"
identify the need for holistic approaches to safety-related infrastructure
improvements, and provide evidence of effectiveness and good practice,
as do the "IHT Rural Safety Management Guidelines",
the DTLR "Good Practice Guidelines" and RoSPA's "Road
Safety Engineering" manual.
Traffic calming schemes remain one of the most
effective methods of reducing vehicle speeds in urban areas, and
are particularly effective at reducing child pedestrian casualties.
20 mph zones have proven particularly effective in reducing accidents
involving child pedestrians and cyclists. RoSPA also supports
the introduction and expansion of Home Zones and Quiet Lanes.
Motorists often claim that it is sometimes difficult
to know what the speed limit is on a particular stretch of road.
The Government should consider how they can best ensure that the
speed limit is always clearly and consistently marked. Greater
use of speed limit repeater signs and road markings should be
considered. Some drivers are confused about the meaning of the
national speed limit sign (white circle with diagonal black bar)
which means different speed limits on different types of road.
This sign should be phased out and replaced with the actual speed
Road policing is essential. The Home Office
should set road policing as a key objective for police forces
and ensure that resources are in place to deliver on this objective.
There has been mixed reaction to speed cameras,
which have received much media coverage recently following the
netting off scheme which allows some of the fine revenue to pay
for the costs of camera enforcement activities. But, accident
data clearly shows that they are effective. The first speed cameras
in the UK were installed in West London in 1992. In the first
three years of operation, at the camera sites they reduced the
number of people killed by 70 per cent and the number seriously
injured by 27 per cent.
A study in 1996 found that speed cameras reduced casualties by
about 28 per cent.
On average, at the camera sites in the Netting-off pilot scheme,
47 per cent (about 109 people) fewer people were killed and seriously
injured and there were 35 per cent fewer crashes.
Motor manufacturers could play a much more prominent
role in reducing the number of people killed and injured in speed-related
road accidents. Manufacturers continue to produce cars and motorcycles
that are capable of achieving speeds of 160 mph and more. RoSPA
believes that the European Commission, national governments and
the motor industry should work together to develop restrictions
on the top speeds and power of new cars and motorcycles.
Modern cars provide a smooth, quiet drive, even
at very high speeds, and therefore drivers are often insulated
from any real sensation of the speed at which they are travelling.
The vehicle's power means that it is very easy to creep above
the speed limit. Indeed, drivers often cite this as a reason for
speeding. Manufacturers should consider how they can design cars
so that drivers have more awareness and receive better information
about their actual speed. For example, the design of the speedometer
is often very unhelpful. On many speedometers, the dial shows
20mph and 40mph, but not 30mph or 70mph. Placing 30mph in the
12 o'clock position on the speedometer dial might raise drivers'
awareness of their speed, particularly on urban roads.
Intelligent Speed Adaptation
Intelligent Speed Limiters perhaps offer the
best opportunity for vehicle technology to influence driving behaviour.
These involve external devices on the roadside which communicate
with a corresponding device on passing vehicles and can either
alert the driver to voluntarily reduce their speed (Driver Select
System) or physically prevent the vehicle from exceeding the speed
limit on the particular road (Mandatory System). Trials by Leeds
University and the Motor Industry Research Association (MIRA),
found that the Mandatory System successful reduced excessive speed,
particularly in areas where drivers are renowned for being poor
at adapting their speed, for example in rural villages. However,
drivers tended to disengage the voluntary system when the surrounding
traffic was speeding, and preferred to be able to turn the system
off when they felt vulnerable or under pressure from other drivers.
The development of Intelligent Speed Adaptation
offers very significant opportunities for influencing drivers'
choice of speed. Further research is needed to assess whether
taking vehicle control away from drivers would have any adverse
affects, but the development and implementation of this technology
should be strongly encouraged.
Safer Car Fronts
As already noted, higher speeds means more severe
injuries, especially to pedestrians. It is estimated that safer
car fronts would save about 2,000 lives and 18,000 serious injuries
annually on EU roads, and could reduce serious and fatal pedestrian
injuries in Britain by 20 per cent. It is extremely unfortunate
that the European Commission has recently decided to accept a
Negotiated Agreement proposed by the motor industry, which is
much less stringent than a mandatory European Directive based
on the four crash tests developed by the European Enhanced Vehicle
Safety Committee Working Group 17 (EECV WG 17).
Company car drivers and others who drive for
work are more likely to speed. RoSPA has been campaigning since
1996 for employers to adopt the Management of Occupational Road
Risk (MORR) and address the risks created when their employees
use the road as part of their work as part of their health and
safety at work procedures. The Work-Related Road Safety Task Group
has recently confirmed that at-work drivers are involved in between
25-33 per cent of road accidents and has made several recommendations
to help ensure that employers manage the safety of their employees
whilst at work on the road. RoSPA believes that the government
and HSC should allocate appropriate resources to enable the report's
recommendations to be implemented.
Employers should identify high-risk drivers
and high-risk journeys and set schedules that are generous enough
to ensure that drivers are not time-pressured into speeding. They
should make it clear that they expect all employees to comply
with posted speed limits when driving in the course of their work
and that failure to do so will be regarded as a serious matter.
They should consider the speed performance of their company vehicles,
assess driver competence and provide appropriate driver training.
RoSPA is developing a "Company Vehicle Speed Code" to
provide advice to employers (copy at Appendix A).
There is no doubt that driving at an inappropriate
speed is one of the most serious road safety problems on Britain's
roads, and causes death and injury to thousands of people each
year. Unfortunately, the danger caused by speeding drivers has
not yet been accepted by the public in the same way as the danger
caused by drink-drivers.
A co-ordinated speed management strategy must
include education, training and publicity, highway engineering
and design, vehicle engineering and enforcement measures. Employers
in particular have a potentially powerful role to play in influencing
employee driver attitudes and behaviour. But ultimately, the public
as a whole needs to be persuaded that driving at inappropriate
speeds is not a minor, technical offence that everyone commits,
but a serious, dangerous and anti-social activity in which the
speeding driver places his/her own convenience above the safety
and well-being of other people.
27 "New Directions in Speed Management-A Review
of Policy", DETR, 2000. Back
"Vehicle Speeds in Great Britain 2000, DTLR. Back
Stradling, "Young Driver Attitudes", DETR Speed Review
Seminar Proceedings, 1999. Back
Webster and Wells: The Characteristics of Speeders: TRL 440. Back
Silcock et al: What Limits Speed? Factors that affect how fast
we drive: AA FRSR. Back
Forsyth: Cohort Study of Learner and Novice Drivers: TRL 372. Back
Burgess and Webley: Evaluating the Effectiveness of the United
Kingdom's National Driver Improvement Scheme: DTLR: 2000. Back
West London Speed Camera Demonstration Project: Highways Agency
Cost Benefit Analysis of Traffic Light and Speed Cameras: Police
Research Group: 1995. Back
"Cost Recovery System for Traffic Safety Cameras, First
Year Report", DTLR, 2001. Back
Carsten et al, "User Trials with Intelligent Speed Limiters",
DETR, Behavioural Research in Road Safety, Tenth Seminar, 2000. Back
Work Related Road Safety Task Group, "Reducing At-work Road
Traffic Incidents", HSE 2001. Back