Speed management

RoadSafe believes that eliminating excessive speed will save lives. The challenge is for driving at inappropriate speed to be seen as anti social.

RoadSafe works with others to:

  • Support and promote programmes of coordinated action in a whole range of areas including engineering, technology, training, communication, regulation and its enforcement.
  • Develop integrated initiatives to encourage stakeholders to introduce sensible speed policies and modern technologies to give better driver information.
  • Identify and promote local successful speed reduction initiatives and policies, then campaign to have them adopted nationally.

The faster one drives, the more likely a crash and the higher the risk of severe injury. The exact relation between speed and crashes depends on many factors. The injury severity of the vehicle occupants in a crash, for example, is not only determined by the collision speed but also by the mass difference between the vehicles. With regard to the crash rate, speed has a more prominent role in more complex situations like on urban roads than on less complex roads like motorways. Whatever the case, the effect of speeding measures is determined by absolute driving speeds, road types and speed differences between vehicles.

Download RoadSafe's policy on speeding 

Research from the Transport Research Laboratory

TRL has provided evidence of three different types on the effect of speed on crashes and collisions.

  • Studies of individual drivers show that when exceeding the average speed by 25% a driver is about 6 times as likely to be involved in an incident in comparison with a driver adopting the average speed. This is similar to the risk associated with alcohol at the legal limit of 80mg/100ml blood alcohol content.
  • Studies of road sections show that for roads of each type, the number of crashes and collisions increases with increasing average speed – the effect varies on different road types and is strongest for the slowest roads. A ball-park figure is that each 1mph reduction in average speed is accompanied by a 5% reduction in accidents.
  • Traffic calming measures (e.g. road humps and chicanes) in 20mph zones have reduced average speeds by about 10mph and resulted in a 50% reduction in collisions. Measures adopted in rural villages have reduced average speeds by about 5mph and resulted in at least 20% fewer collisions.
  • Research at Napier University shows that individuals are aware that speeds they normally adopt when alone are actually unsafe. For example, participants described situations in which they would slow down such as the presence of a speed camera or child in the car. This suggests that individuals know that if they see a camera they would need to slow down because they would be exceeding the limit. 

Changing attitudes to speed need to relate to influences on speed:

  • Obligations - such as keeping appointments, picking up kids, and generally meeting the tight time schedules of modern life.
  • Opportunities - that allows speeding to take place, such as a fast car and a clear road.
  • Inclinations - performing behaviours in accordance with personal preference such as I like to speed as it feels good.

Road safety professionals recognise that speed management is a very important tool for improving road safety. However, improving compliance with speed limits and reducing unsafe driving speeds are not easy tasks. Many drivers do not recognize the risks involved and often the perceived benefits of speeding outweigh the perceived problems that can result.

One such professional Dan Campsall, Communications Manager for the Thames Valley Safer Roads Partnership and a director of Road Safety Analysis Limited, has put forward a thought brief. It takes a look at some of the ways in which technology and innovation could answer the pressing needs of the road safety community to continue delivering the world's safest roads under very different economical and political conditions.


Three valuable fact sheets are available from SWOV - The Dutch Institute of Road Safety Research:

Visit the Department for Transport website for more information.


An excellent international manual consisting of a series of 'how to' modules is now available. It provides evidence of why speed management is important and takes the user through the steps needed to assess the situation in their own country. It then explains the steps needed to design, plan and implement a programme, including how to obtain funding, set up a working group, develop an action plan and, if necessary, introduce appropriate legislation. It considers the potential role of measures involving engineering and enforcement, as well as using education to change speed related behaviour. Finally, the manual guides the user on how to monitor and evaluate the programme so that the results can be fed back into programme design. For each of these activities, the document outlines in a practical way the various steps that need to be taken