Memorandum submitted by the Slower Speeds
Initiative
SUMMARY
We discuss the use of technology to reduce speed.
Speeding is the main form of motoring offence dealt with by the
police. The problem should be addressed at source through vehicle
design and technology to aid driver compliance with speed limits.
Controversy has prevented the most effective use of speed cameras.
To achieve wider speed limit compliance cost-effective deployment
strategies for speed cameras would be evidence based. Time over
distance enforcement cameras should be used more. The potential
of intelligent road studs should be explored. Event data recorders
would produce better evidence for prosecutions while reducing
the investigative burden on police. Traffic policing should make
full use of available and emerging enforcement technology to reduce
the wider impacts of speed and ensure more equitable and less
damaging use of the road network.
THE SLOWER
SPEEDS INITIATIVE
The Slower Speeds Initiative was founded in
March 1998 by the Children's Play Council, CTC, the Environmental
Transport Association, the Pedestrians Association, the Pedestrian
Policy Group, the Road Danger Reduction Forum, RoadPeace, Sustrans
and Transport 2000. We work to raise awareness of the benefits
of lower speeds in controlling the adverse impacts of our transport
system and enabling the use of sustainable transport modes. Technology
should be used systematically—from vehicle design to traffic
management—to reduce rather than exacerbate the impacts
of speed.
1. Technologies to increase compliance with
speed limits—reducing the burden on the police by dealing
with the problem at source
Getting the right balance between traffic policing
and technology should start with the use of technology to reduce
the overall scale of the task.
The scale of the problem
Speed limits are rarely enforced; nevertheless
speeding is a major burden on the police. The majority of drivers
speed (Department for Transport 2005). In 2001 motoring offences
accounted for nearly half of the offences dealt with each day
by the police (Home Office 2001). Speeding is the largest motoring
offence group dealt with by the police, 31% of all motoring offences
in 2002 (Ayres et al 2004). The number of speeding offences
dealt with by the police has been rising steadily year on year
with the increasing use of speed cameras.
A significant amount of police time is taken
up in dealing with road crashes. In 1994 it was estimated to be
around 11% of traffic police time (Hooke et al 1996).
Nearly 3,500 people are killed annually on our
roads and speed has been found to be the main contributory factor
in about a third of these (Mosedale and Purdy 2004). This makes
speeding the leading cause of violent death in the UK. It is also
the anti-social behaviour of greatest concern to the public (Wood
2004). It is obvious that reducing the burden of speeding on the
police as well as society would be enormously beneficial.
Vehicle design
The problem of speeding and therefore the scale
of the enforcement burden is very largely a result of vehicle
design. The problem should be reduced at source through motor
vehicle construction and use regulations. Intelligent speed adaptation,
limits on top speed and acceleration should be a priority for
Government.
In-car information
Better in-car information to drivers should
be introduced to make compliance with all speed limits much easier.
Speedometer design could ensure that drivers are always aware
of their speed. Increased speed limit enforcement and the rules
on camera signing and visibility have created a rudimentary intelligent
speed adaptation system. In-car speed warning information is now
widely available. Clear signing of speed limits and a more effective
camera deployment strategy would stimulate this market whilst
helping to deter speeding.
Event Data Recorders
In-car technology to monitor how a car is being
driven would also reduce the enforcement burden on the police.
Many cars are already fitted with an array of electronic devices
(event data recorders or EDRs) to improve crash survivability
for occupants, assist maintenance, allow tracking in the case
of theft and even call emergency services. EDRs associated with
air-bags can take readings of speed and accelerator and brake
pedal positions at intervals of a few seconds and can store data
on minor impacts and collisions for up to 60 days (Ward 2002).
When drivers know that this information is being recorded crashes
are reduced by 20 to 30% (SWOV 1997; PACTS 1999).
An Irish insurance scheme uses a black box system
to discourage speeding by young drivers. They pay around £500
to fit a device that warns them when they exceed a speed limit
and records location and speed for later analysis by the insurer.
Drivers who stick to the speed limit get lower premiums. In addition
to paying for itself, the system is reducing crashes and claims
(Byrne 2003). "Pay-as-you-drive" insurance policies
in the UK using such technology and available digital maps could
provide incentives in the short term for the voluntary uptake
of speed reducing technology.
Top speed limited vehicles equipped with event
data recorders could be used to reduce repeat offending as a part
of sentencing, on the model of the "alco-lock".
Appropriate speed limits
Police concerns about enforceability constitute
one of the major obstacles to the lower speed limits sought by
communities around the country. Using technology to reduce the
enforcement burden on police would help to remove this barrier
to more appropriate speed limits. Lower average speeds will in
turn reduce the burden of road crashes on society, as well as
enabling more sustainable forms of transport.
2. Technologies to enforce speed limits
Lessons from the safety camera experience
The safety camera experience demonstrates that
the technology of enforcement, and its effectiveness, cannot be
treated in isolation from political and social factors. The constraints
under which Safety Camera Partnerships have had to operate mean
that it cannot be assumed that speed cameras have been used as
effectively as they could be.
It should have been easy to foresee that a sudden
increase in speed limit enforcement would generate controversy,
given the statistics on rates of speeding, evidence on driver
attitudes to speeding and knowledge of speed limits (Silcock et
al 1999) and the power of the motoring lobby in the media.
There was insufficient preparation of the public and professionals,
including the police, for the roll out of the policy. The evidence-base
for the policy has still not been properly disseminated or discussed.
In reaction to controversy the Government imposed
rules for camera visibility and siting criteria that reduced the
camera sphere of influence and encouraged drivers to speed outside
the range of cameras. Both of these effects could be expected
to counteract the casualty reducing potential of the technology.
The rules also had the effect of increasing reliance on mobile
cameras which not only require a police presence and thus increase
costs but are also less effective than fixed cameras at reducing
speed and casualties (Gains et al 2005).
By implying that speeding is only of real concern
some places, for special reasons (a very serious crash history)
and by positively encouraging speeding away from cameras the presentation
of policy and the deployment strategy imposed on Safety Camera
Partnerships weakened the validity and intelligibility of the
policy and fed controversy.
While it may not yet be universally accepted,
the evidence base for the use of speed cameras is well-established,
including in research commissioned by the Department for Transport.
Even within the constraints imposed on them four years of work
by Safety Camera Partnerships have extended the evidence base.
In general, crash frequency and severity are correlated with speed.
Depending on the type of road, every 1 mph reduction in average
speed will reduce crashes are by between 2-7%. A mere 2 mph reduction
in average speeds across the entire road network would prevent
more than 200 deaths and 3,500 serious casualties a year (Taylor
et al 2000).
The strong relationship between speed and crashes
indicates that the aim of enforcement should be widespread compliance
with speed limits. Automatic detection is so far the best way
we have to achieve this. It should free police for "live"
traffic duties. Reducing average speeds would also help to reduce
the danger of traffic violations not detectable by cameras and
not occurring within the field of vision of a traffic officer.
The threshold speeds which trigger enforcement
are well above, and increasingly known to be above, the speed
limit. The speed crash relationship indicates that this will also
limit the casualty reduction potential of speed cameras. The official
rationale for high thresholds is that the police want to avoid
disputes about marginal violations in order to be certain of securing
a conviction. But there is also anecdotal evidence that thresholds
are high in order to reduce the throughput of penalties. This
is a bad reason to tolerate lawbreaking and danger. Targets to
progressively reduce thresholds and harmonise them across police
force efforts would increase the effectiveness of speed cameras.
Digital speedometers and event data recorders would reduce dispute
over actual speeds.
A more effective deployment strategy
To encourage their compliance with speed limits,
drivers should have a high degree of certainty that the limit
is being enforced with a high degree of uncertainty about where
and when it is being enforced (Kallberg et al 1998). In
theory, drivers should need nothing more than a sign reminding
them of the speed limit and the commitment to enforce, accompanied
by publicity at a national and local level about the reasons for
enforcement.
The speed-crash relationship shows that enforcing
speed limits wherever speeding poses an undue risk will help to
prevent casualties as well as to reduce them. Speed cameras would
be made much more effective if they were inconspicuous and deployed
randomly.
More effective enforcement technology
The French experience of speed limit enforcement
contrasts sharply with the UK. In 2002 President Chirac instigated
a successful and popular crackdown on speeding. One element of
the strategy is a fully automated digital system of detection
and enforcement which issues a penalty notice within 48 hours
of the offence. Steve Stradling has noted that the long time period
between offending and charging typical in the UK is one cause
of driver resentment of speed cameras.
The aim of speed limit enforcement should be
deterrence. The locations of even inconspicuously sited fixed
cameras can in time become known to drivers, with a reduction
in their deterrent effect. Time over distance camera technologies
(for example SPECS digital cameras) using Automatic Number Plate
Recognition overcome this problem by calculating average speed
between two points and automatically recording drivers travelling
over a threshold speed. This is perceived to be fairer since drivers
are not penalised for incidental violations. It is more effective
in reducing casualties and speed since it secures more consistent
compliance with the speed limit. The fourth year report on safety
cameras showed that distance of over time cameras reduced speeding
on average by 53% and completely eliminated high end offences
(exceeding the speed limit by more than 15 mph). There should
be much wider use of this technology.
Another technology which could have huge potential
is the intelligent road stud (IRS). The studs are set into the
road. Protruding only 4mm, they are very inconspicuous. They can
house lighting systems, weather and road conditions sensors, infra-red
speed detectors and digital video cameras. They can collect and
transmit data to road side cabinets which can be connected to
traffic control systems. IRS technology is in use in the UK and
abroad as a cheap and effective means detecting weather and lighting
conditions and providing visual guidance to drivers when required.
It appears that IRS technology could combine
vehicle activated driver information and warning systems with
enforcement. Speeding drivers could activate warning lights indicating
that they should slow down. If they failed to heed the warning,
they could then trigger camera studs to record their speed and
issue violation notices. The system could even confirm to drivers
that it had switched from a warning to enforcement mode.
3. Technologies for fair and efficient prosecution
of road traffic law
The speed crash relationship shows that even
small differences in speed can make a difference to whether a
crash occurs and the severity of the outcome when it does. Current
crash investigation methods can only give very crude estimates
of the speeds involved. Advanced braking systems eliminate skid
marks which have been relied on in the past to estimate speed.
The poor quality of data on speed leads to injustice
in the courts when gross negligence cannot be proved and drivers
who kill or maim are let off with very light or even no sentencing.
Poor data also reinforces a general lack of sensitivity on the
part of the police and coroners to the importance of speed as
a factor in crashes.
Event data recorders would solve this problem.
Police investigating crashes involving death or serious injury
would have reliable and accurate data. This would not only increase
justice for victims of road crashes but would reduce the investigative
burden on the police. There would be wider benefits if the data
were also available to emergency and medical services in dealing
with crash victims (Martinez 2003) and to road safety researchers.
4. Technology to support a wider role for
traffic policing
Casualty reduction is an important aim for roads
policing but it is not the only one. As the 2005 joint Roads Policing
Strategy acknowledges, traffic policing should also reduce anti-social
use of the roads. Speeding drivers intimidate and endanger all
road users but their impacts disproportionately affect the most
vulnerable—pedestrians and cyclists, young and old. Speeding
increases severance, noise and pollution in communities. It results
in excessive emissions of CO2.
The importance of road policing to a more equitable
and sustainable transport system was recognised by Her Majesty's
Inspectorate of Constabulary in its 1998 report on road policing:
"The Integrated Transport Policy aims to
direct more people from cars to public transport, bicycles and
walking, particularly commuters and children travelling to and
from school. This presupposes a safe environment with little fear
of crime, disorder and injury, which is an implicit future demand
on the police." (Her Majesty's Inspectorate of Constabulary
1998, para 1.19)
The police should make full use of available
and emerging technology to protect the rights of all road users
and ensure equitable and less damaging use of the road network.
CONCLUSIONS
The most important application of technology
in traffic law enforcement would be to eliminate the problem through
vehicle design. In-car technology should be introduced to aid
compliance, increase driver responsibility and improve the quality
of evidence for prosecution. Existing cameras should be used more
effectively by being deployed inconspicuously to maximise compliance.
Time over distance enforcement technologies should be used more
widely. The potential for intelligent road studs to warn and enforce
should be tested. Police use of technology should aim to make
road transport more equitable and sustainable.
17 February 2006
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