Inappropriate Speed - January 2016

Also available to download: Inappropriate Speed


Inappropriate speed contributes to around 10% of all injury collisions reported to the police, 13% of crashes resulting in a serious injury and 24% of collisions which result in a death.1 This includes both ‘excessive speed’, when the speed limit is exceeded but also driving or riding within the speed limit when this is too fast for the conditions at the time (for example, in poor weather, poor visibility or high pedestrian activity).

In 2014, 282 people were killed in crashes involving someone exceeding the speed limit and a further 126 people died when someone was travelling too fast for the conditions.1

Drivers and riders who are travelling at inappropriate speeds are more likely to crash and their higher speed means that the crash will cause more severe injuries, to themselves and/or to other road users. Inappropriate speed also magnifies other driver errors, such as driving too close or driving when tired or distracted, multiplying the chances of these types of driving causing an accident.

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. It removes the driver's safety margin and turns near misses into crashes.

Around two-thirds of crashes in which people are killed or injured occur on roads with a speed limit of 30 mph or less. At 30 mph vehicles are travelling at 44 feet (about 3 car lengths) each second. One blink and the driver may fail to see the early warning brake lights; a short glance away and the movement of a child behind a parked car will be missed. Even in good conditions, the difference in stopping distance between 30 mph and 35 mph is an extra 21 feet, more than 2 car lengths.

If average speeds reduced by 1 mph, the accident rate would fall by approximately 5%.23 This varies slightly according to road type, so that a 1 mph reduction in average speed would reduce accident frequency by about:

  • 6% on urban main roads and residential roads with low average speeds
  • 4% on medium speed urban roads and lower speed rural main roads
  • 3% on the higher speed urban roads and rural single carriageway main roads.

If an individual drives more than 10 - 15% 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 Injuries4

Car Drivers

The risk of injury in any collision is influenced by many factors, including the vehicle’s speed, its design, strength and occupant protection systems, whether the occupants were wearing seat belts, the nature of the other vehicle(s) or object(s) struck, and the medical care received by the victims.

However, car drivers are much more likely to be injured in collisions at higher speeds. On average, in frontal impacts, belted drivers have a 17% risk of being fatally injured in impacts at 40 mph and a 60% risk at 50 mph. Having said that, half of drivers who were fatally injured, were in an impact of 34 mph or less.

Side Impacts

When cars are hit from the side, drivers are at a much greater risk: in a collision at 40 mph the risk of a belted driver being killed is 85%.


Multiple studies (see Table 1 below) have shown that pedestrians are more likely to be severely or fatally injured in when hit by cars at higher speeds, and particularly when the car is travelling more than 30 mph.

An analysis of vehicle speed in pedestrian fatalities in Great Britain4, found that 85% of pedestrians killed when struck by cars or car-derived vans, died in collision that occurred at impact speeds below 40mph, 45% at less than 30 mph and 5% at speeds below 20 mph.

The risk of a pedestrian who is hit by a car being killed increases slowly until impact speeds of around 30 mph. Above this speed, the risk increases rapidly, so that a pedestrian who is hit by a car travelling at between 30 mph and 40 mph is between 3.5 and 5.5 times more likely to be killed than if hit by a car travelling at below 30 mph. However, about half of pedestrian fatalities occur at impact speeds of 30 mph or below. Elderly pedestrians have a much greater risk of suffering fatal injuries than other age groups.

Table 1: Pedestrian Fatality Risk 4



Number of injuries examined

Risk of fatal injury at 30mph

Increased risk of fatal injury between 30 and 40mph





5.5 times more likely



490 (excludes children under 15)


3.5 times more likely





4.5 times more likely

Who Speeds?5

  • On 30 mph roads in built-up areas, 45% of car drivers exceed 30 mph and 15% exceed 35 mph.
  • On 40 mph roads in built-up areas, just over one fifth (21%) of car drivers speed, and 7% go faster than 45 mph.
  • On single carriageway 60 mph roads in non-built-up areas, 7% of drivers speed but only 1% go over 70 mph
  • On 70 mph dual carriageways in non-built-up areas, over one third of car drivers (37%) exceed the speed limit, with 10% of those going over 80 mph.
  • On motorways in non-built-up areas with 70 mph limits, almost half (46%) of car drivers exceed the speed limit, with 11% going faster than 80 mph.

Research 6 suggests there are three types of drivers:

  • Compliant drivers who usually observe speed limits (52% of drivers)
  • Moderate speeders who occasionally exceed speed limits (33% of drivers)
  • Excessive speeders who routinely exceed speed limits (14% of drivers)

However, even the moderate speeders exceed 30 mph limits fairly regularly. Excessive speeders normally ignore the 30 mph limit, and often by a wide margin.

Types of Speed-related Crashes7

  • Most collisions involved some loss of control of the vehicle, usually on a bend. Other reasons included vehicles travelling around blind bends, or following other vehicles too closely.
  • Collisions were more likely on unclassified rural roads, with excess speed being more likely on 30 mph roads, and inappropriate speed on 60 mph rural roads.
  • Male drivers under 30 years old, and especially under 21 years old, were more likely to be in speed-related collisions.
  • Car drivers and motorcyclists were more likely to be in speed-related collisions than drivers of other vehicles.
  • Drivers who crashed while exceeding the speed limit were more likely to be ‘aggressive driving’, ‘careless, reckless or in a hurry’, ‘impaired by alcohol’ or in a ‘stolen vehicle’.
  • Drivers who crashed while travelling at inappropriate speed were more likely to be ‘careless, reckless or in a hurry’, ‘vision affected by road layout’, ‘vision affected by rain, sleet, snow or fog’ and ‘slippery road (due to weather)’.

How Can Speed Related Accidents Be Reduced?

Driver Education

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 often not regarded 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 acceptance and ownership of the problem of illegal and inappropriate speed.

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.

Road safety publicity campaigns such as the Government’s Think! Road Safety Campaign and the Scottish Government’s “Foolsspeed” campaign are strongly supported by RoSPA.

Motor manufacturers, national press, TV and advertisers should not glamourise 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.

Driver Training

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% of drivers take any further driving instruction after passing their test8. Therefore, there is a need to develop new ways of encouraging drivers to continue to develop their driving skills after the test.

RoSPA's report, "Refresher Driver Training", 9 examines the low awareness of post-test training options and motivations and deterrents for taking such training. A leaflet, "Get More From Your Driving" 10 is also available to promote refresher training.

The Driving Test

Over the last 15 years or so, the driver training regime and the Driving Test in Britain has been enhanced in a number of ways, including by introducing the Theory Test, the Hazard Perception Test, Pass Plus and independent driving (where candidates have to drive to a destination without step-by-step directions) in the test. Further changes to the driving test are currently being trialled. The Government also promotes post-test driver training, and the concept of regular refresher training.


Graduated Driver Licensing (GDL) also 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. Research1112 has found that fatal collisions among young drivers reduced by 9% to 60%, and overall casualties by 5% to 32% in countries that introduced GDL schemes.

It has been estimated that a GDL system in Great Britain would result in 81 to 114 fewer deaths and 538 to 872 fewer serious injuries annually (depending on the extent of night-time and passenger restrictions applied)13. Another analysis of the effects if the system only applied to 17 to 19 year old drivers concluded that in an average year, it could save 4,478 casualties, including 433 deaths and serious injuries and deliver social and economic benefits valued at £200.1 million.14

Speed awareness courses provide a good opportunity to educate drivers who have committed speeding offences. Many drivers seem to believe that their car will not do less than 35 mph. Education, training and publicity should seek to help drivers understand that they can control their vehicle sufficiently to drive within the 30 mph speed limit.

Highway Design and Engineering

Drivers’ choice of speed is partly dependent on the characteristics of the road on which they are driving, and drivers’ perception of what is a safe speed on a particular road will often differ to that of other road users, such as pedestrians, pedal cyclists and horse riders. Therefore, it is important that road design gives drivers the right messages about the maximum safe speed.

Ways of improving the road environment to encourage drivers to drive at appropriate speeds are discussed in "Helping Drivers Not To Speed"15 and advice on how to avoid inadvertently exceeding the speed limit is provided in RoSPA’s “Top Ten Tips To Stay Within the Limit”.16

Safer roads benefit all road users, but especially those who are most vulnerable: pedestrians, cyclists, motorcyclists, children and the elderly.

20 mph Zones and 20 mph Limits

The measures that are most effective in reducing vehicle speeds and thereby reducing road death and injury are area-wide traffic calming schemes and 20 mph zones.

RoSPA strongly supports the use of 20 mph zones as they are an effective means of reducing road crashes and casualties. They are very effective at protecting our most vulnerable road users, including children, pedestrians and cyclists, and significantly decrease the risk of being injured in a collision. RoSPA encourages their greater use, especially in residential areas.

RoSPA supports and encourages the wider use of 20mph limits. They have been shown to reduce traffic speed, although not as much as 20mph zones with traffic calming. However, they are considerably less expensive to implement, which means that wider areas can be covered. They also provide additional benefits, such as encouraging more physical activity, such as walking and cycling. They can also greatly improve the character of a residential area and quality of life of the residents.

The evidence about 20 mph Zones and Limits is summarised in RoSPA’s “20mph Zones and Limits” factsheet17

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. A wide range of good practice guidelines have been published by the Department for Transport, the Institute of Highways and Transportation (IHT) and RoSPA.


Roads policing is a fundamental and irreplaceable activity, which plays a key role in saving lives and minimising injury on the road. In order to do this effectively, roads policing must be given its rightful priority by the government and the Police Service, and be adequately resourced. The Police have many priorities, including tackling many forms of violent crime, all of which are extremely important. They must, therefore, allocate and prioritise their limited resources to the best possible effect. The level of death and injury caused by poor, and often illegal, behaviour on the road far exceeds the number of people killed through any other form of crime. Accordingly roads policing must be one of the top priorities.

Safety Cameras

Cameras are an effective way of persuading drivers not to speed, and thereby reducing the number of people killed and seriously injured. An independent review18 of more than 4,000 safety cameras over a four year period showed that cameras significantly reduced speeding and collisions, and cut deaths and serious injuries at camera sites by 42%.

A review of the evidence of the effectiveness of speed cameras in 201019 examined data from the above four year study plus many other UK and international studies along with data on traffic speeds, collisions and casualties. Taking into account other factors that might reduce speeds, and speed-related crashes and casualties, such as the downward national trend in casualty numbers, regression to mean (as many cameras were installed at sites with untypically high numbers of casualties, casualties might have fallen back towards the average level anyway) and drivers diverting to avoid cameras, concluded that in the year ending March 2004, cameras at more than 4,000 sites across Great Britain prevented some 3,600 personal injury collisions, saving around 1,000 people from being killed or seriously injured (KSI).

The report also concluded that if safety cameras were decommissioned about 800 extra people across Great Britain could be being killed or seriously injured each year.

A later report by the same author, using data released in 2011 as part of a government move to make speed camera operations more transparent to the public, showed a smaller, but still sizable, benefit from the use of speed cameras in the areas where data were analysed. Analysis of data for 551 fixed speed cameras in 9 different areas shows that, on average, the number of fatal and serious collisions in their vicinity fell by 22% after their installation. There was also an average reduction of 14% in personal injury collisions in the vicinity of the 551 cameras. However, the research also highlighted 21 camera sites where collisions appears to have risen and should be investigated further.20

Further research studies analysing the effects of safety cameras can be found in the Road Safety Observatory “Safety Cameras” review.21

Vehicle Engineering

Vehicle technology is changing rapidly, as crash avoidance systems and autonomous technology are developed.

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.

Speed Warning technology

Speed warning technology gives the driver a visual and/or audible warning if s/he exceeds a pre-set speed. Some systems also inform the driver of the speed limit of the road they are using, and/or of safety camera sites ahead. They are often, but not always, incorporated into SatNavs, but some vehicles have built-in technology.

It can help to keep drivers aware of their speed and encourage them not to exceed speed limits, but drivers should take care not to use the technology to ‘get away’ with speeding by relying on it warning them when they are approaching safety cameras.

They should also choose their pre-set speed according to the type of road on which they will mostly be driving. If mainly driving on 30mph roads, the warning should be set at 30mph; if driving on motorways, setting it at 70mph makes more sense. The pre-set speed should be set before the start of a journey.

Intelligent Speed Adaptation

Technology which can prevent drivers from exceeding the speed limit on any particular road is being developed and tested. The latest field tests22 show that this “is now a mature technology which is capable of delivering substantial reductions in excessive speed and thereby considerable benefits in terms of safety.”

Depending on how the technology is implemented, over the 60 year period from 2010 to 2070, it would be expected to reduce fatal accidents by between 10% (approximately 15,400 fatal accidents) and 26% (approximately 43,300 fatal accidents), serious injury accidents between 6% (96,000 accidents and 21% (330,000 accidents), and slight injury accidents by between 3% (336,000 accidents and 12% (1.3 million accidents).

One of the requirements for the widespread implementation of this technology is a digital map showing the speed limit on every road in the country, which can easily and regularly be updated, including taking account of speed limit changes due to road works. Ultimately, this will make it possible to display the speed limit of every road within the car, so that a driver can constantly be aware of the limit.

Some Satellite Navigation devices can also advise drivers of the speed limit of the road, although drivers should still primarily rely on the legal road signs, in case the device is not up to date or there is a temporary limit in place.


Driving is the most dangerous work activity that most people do. Around 150 people are killed or seriously injured every week in crashes involving someone who was driving, riding or otherwise using the road for work purposes.

HSE Guidelines, “Driving at Work”23 , state that “health and safety law applies to on-the-road work activities as to all work activities and the risks should be effectively managed within a health and safety system”.

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 has produced a Guide, "Driving for Work: Safer Speed Policy"24 , to help employers and line managers to ensure that their staff are not tempted or pressurised into driving at inappropriate speed. It includes a sample ‘Safer Speed Policy’ which can be adopted as written or adapted to suit an organisation’s needs.


There is no doubt that 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 have a powerful role to play in influencing employee driver attitudes and behaviour. But ultimately, all drivers and riders need 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.


  1. "Contributory Factors to Reported Road Accidents”, Article in “Reported Road Casualties Great Britain, 2014”, Department for Transport, 2015
  2. "Speed, Speed Limits and Accidents” Finch et al, TRL Project Report 58. TRL, 1994
  3. "Effects of Drivers Speed on the Frequency of Road Accidents”, Taylor et al, TRL Report 421, 2002
  4. "Relationship between Speed and Risk of Fatal Injury: Pedestrians and Car Occupants”, Road Safety Web Publication No.16, Department for Transport, September 2010
  5. "Free Flow Vehicle Speeds In Great Britain 20104 Tables SPE0101 and SPE0102, DfT 2015 " Tables SPE0101 and SPE0102, DfT 2011
  6. "Understanding Inappropriate High Speed: A Quantitative Analysis”, Road Safety Research Report 93, Stradling, DfT, 2008
  7. "The Characteristics of Speed Related Collisions”, Road Safety Research Report 117, Department for Transport, Sept 2010
  8. "Accidents Rates and Behavioural Characteristics of Novice Drivers in the TRL Cohort Study”, TRL Report 293, R West, 1998
  9. "Refresher Driver Training”, RoSPA, 2005
  10. "Get More From Your Driving”, RoSPA, 2015
  11. "Hartling L, Wiebe N, Russell KF, Petruk J, Spinola C, Klassen TP. Graduated driver licensing for reducing motor vehicle crashes among young drivers. Cochrane Database of Systematic Reviews 2011
  12. "Kinnear N, Lloyd L, Helman S, Husband P, Scoons J, Jones S, Stradling S, McKenna F and Broughton J (2013). Novice drivers: Evidence Review and Evaluation. Pre-driver training, Graduated Driver Licensing and the New Drivers Act.TRL Published Project Report (PPR673) Crowthorne: Transport Research Laboratory.
  13. "Sarah S Jones, Dorothy J Begg & Stephen R Palmer. (2013) Reducing Young Driver Crash Casualties in Great Britain: Use of Routine Police Crash Data to Investigate the Benefits of Graduated driver Licensing.International Journal of Injury Control and Safety Promotion Vol 20, No. 4, 2013
  14. "Kinnear N, Lloyd L, Scoons J, & Helman S (2014). Graduated Driver Licensing: A Regional Analysis of Potential Casualty Savings in Great Britain. RAC Foundation
  15. "Helping Drivers Not To Speed”, RoSPA, 2007
  16. "Top Ten Tips To Stay Within the Limit”, RoSPA, 2014
  17. "20mph Zones and Limits”, RoSPA, 2015,
  18. "The National Safety Camera Programme: Four-year Evaluation Report”, University College London & PA Consulting, 2005
  19. "The Effectiveness of Speed cameras: A Review of Evidence, Prof R Allsop, RAC Foundation, November 2010
  20. "Guidance on Use of Speed Camera Transparency Data (Updated November 2013)”, Prof R. Allsop, RAC Foundation, 2013,
  21. "safety Cameras Review”, Road Safety Observatory, 2016,
  22. "Isa- UK intelligent speed adaptation: Final Report, the University of Leeds and MIRA Ltd, June 2008
  23. "Driving at Work: Managing Work Related Road Safety” INDG 382, HSE & DfT, 2014
  24. "Driving for Work: Safer Speed Policy”, MS 190, RoSPA, 2011

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