Speed enforcement aims to prevent drivers exceeding the speed limit by penalizing those who do. This not only affects the speed violators who actually get caught (specific deterrence), but also those who see or hear that others get caught (general deterrence). Speed enforcement will remain an essential speed management measure as long as the speed problem is not solved in a structural way by road design, engineering measures or in-vehicle technology. There are various tools and methods available for speed enforcement. Police enforcement can be a very effective measure, even though the effects are limited both in time and place. Surveys show that road users are generally fairly positive about it.
What are the general mechanisms of effective police enforcement?
Police enforcement is based on the principle that people try to avoid penalty. Most important is that people have the impression that there is a high chance that they will be penalized when violating a rule (the subjective chance of apprehension). The subjective chance of apprehension is first of all affected by the actual level of enforcement (i.e. the objective chance of apprehension). In addition, it is affected by how much people see or hear about police enforcement. Therefore, the subjective chance of apprehension can be increased by:
- Applying both visible and hidden enforcement activities
- Publicity about specific enforcement activities (e.g. in national or regional media)
- Feedback on the results of enforcement activities (e.g. in national or regional media)
When drivers are caught for a speeding violation, the specific penalties differ in different countries. Generally, the fines are related to the level of speeding: the larger the speed violation, the higher the fine. Speeding at motorways is generally seen to warrant lower fines than speeding on other road types; speeding at working zones is generally given higher fines. All of these systems are only effective in so far as the fines are paid. In countries that apply a penalty point system, penalty points are assigned for the more severe speed violations in addition to a monetary fine. If a speed violation exceeds a certain threshold, the driving license can be suspended for a particular period of time. In some countries convicted drivers can or must follow a driver improvement course after a serious speed limit violation.
Which tools and methods are available for speed enforcement?
There are many tools and methods available for speed enforcement. A main distinction can be made between automatic and non-automatic speed enforcement. With non-automatic speed enforcement a speed violation is detected and the violator is immediately afterwards stopped by a police officer who can either warn or fine the driver. With automatic speed enforcement, the license plate number of a speed-violating vehicle is registered, and several weeks later the license plate holder will receive a fine by mail.
Tools and methods for non-automatic speed enforcement:
- Spot control: radar or laser gun equipment alongside the road (visible or hidden)
- Distance control: conspicuous or inconspicuous police cars
Tools and methods for automatic speed enforcement
- Spot control: fixed or mobile speed cameras
- Distance control: trajectory or section control (control between two points)
Which automatic speed enforcement tools can be used partly depends on the legal system in a particular country and, more particularly, on liability and privacy legislation related to the identification of the license plate holder. Experience shows that a speed camera enforcement programme requires good national and local partnerships working to clear and transparent rules to ensure public acceptability. Achieving compliance requires legislation that enables vehicle owners to be liable for the offence.
UK: safety camera partnerships
In UK a pilot scheme in 2000 among eight police force areas led to a Safety Camera Funding Scheme which now covers the majority of police areas in the country. In order to take part in the scheme partnerships of police and local authority agencies must be established. These are able to recover the costs of operating speed and red light cameras (known collectively as safety cameras) from the fines resulting from enforcement. Any extra revenue from the fines went to central government as with other fines. There are clear guidelines covering where and how safety cameras should be placed, and ensures to be taken to ensure drivers are aware of them (published on www.dft.gov.uk under the Road safety area).
National guidelines require cameras to be clearly visible and to be located primarily at accident sites. Evaluations have indicated a 33% reduction in personal injury accidents at sites where cameras had been introduced, and a 40% reduction in accidents resulting in fatal or serious injuries. But the number of speeding offences detected has reached almost 2 million per year, and emphasis is now being given to ensuring other speed reduction measures are considered fully before cameras are installed, to maintain public support for the programme.
Source: Lynam et al., 2005
The Netherlands: 6 million speed offences recorded automatically
In the Netherlands two developments have been important for the use of speed cameras in the Netherlands: (1) A new administrative law in September 1990 which covers minor traffic offences and which stipulates that in cases involving registration of speed offences by radar, the party in whose name the vehicle is registered is liable and (2) the start of a central bureau of traffic enforcement in 1998 which co-ordinates regional enforcement projects and supervises the monitoring of speed behaviour.
In 2004, the Bureau of Traffic Enforcement had about 800 fixed speed camera poles under supervision of which about 20% actually contains a camera. The cameras rotate amongst the poles. Also, provincial and municipal authorities manage a number of fixed camera poles. According to a website dedicated to providing information about speed checks, the total number of fixed speed camera poles in the Netherlands would be more than 1600. There are currently about 6 million speeding offences recorded annually.
Source: Lynam et al., 2005
France: automatic enforcement of speed violations since 2003
On the 14th of July 2002, the national holiday in France, the French President Jacques Chirac announced that the 'fight against road unsafety' would be one of his three main objectives for the next 5 years. A year later, summer 2003 a road safety action plan was adopted. One of the most important actions concerns the introduction of an automatic enforcement and penalty system for speed violations. In November 2003, the first speed cameras were installed. At the end of 2004 there were 400 speed cameras (232 fixed and 168 mobile) and it is expected that by the end of 2005, there will be 1000 systems in function (700 fixed and 300 mobile). Unlike other countries, every box will hold a camera. Sites are clearly signed and publicised. Revenue can be used for other road safety operations. In the first full year of operation (2004), two million speeding violations were recorded.
Source: Canel and Nouvier, 2004
Sweden: a speed camera box every 4.5 km
In Sweden the police and the National Road Administration carried out a trial of automatic speed cameras from 2002. By the end of 2003, about 500 km of the main roads were covered with camera boxes in which cameras can be placed randomly. A further 250 km was completed in 2004. The total number of boxes was then 335. The total road length covered is 750 km, so there will be a box on average every 4.5 km. Forty four road links are involved. 9 500 vehicles were photographed by speed cameras in 2003 but the driver was only identified in 6 000 cases, and legislation does not yet allow the owner of the car to be held responsible. Some efforts are being made to implement this change in law. Normally cameras are installed on accident prone roads with speed limits of 90 km/h. There is however an increasing use of camera boxes at local speed limits of 70 or 50 km/h at intersections etc. The regions of the Road Administration (7 regions) together with the county police (21 counties) decide on the placement and the number of camera boxes.
Early accident studies are consistent with existing models showing the effect of speed on safety. The preliminary effect on fatal accidents is a reduction of 50% and on all injury accidents 25%. The speed reduction is 5-10 km/h.
How effective is speed enforcement?
First of all, it must be noted that the effects of speed enforcement are very limited to both time and place. When the enforcement stops, the effects will disappear within a few weeks . The effects are largest in the immediate vicinity of the enforcement location, and fade away when distance increases . However, during the enforcement activities and on the enforced roads, the effects of speed enforcement can be very positive. Most evaluation studies looked at automatic enforcement by fixed speed cameras. The effects of non-automatic enforcement have not been studied as systematically as the effects of automatic enforcement. The effectiveness of enforcement depends on many factors, but some elements are essential for success, one of them being publicity.
The best estimate is that automatic speed enforcement results in an accident reduction of 15 to 20% . Individual evaluation studies differ widely in the reported effects. For fixed speed cameras, the effects varied from a 5 to 69% reduction in accidents, a 12 to 65% reduction in injuries and a 17-71% reduction in fatalities . The actual effectiveness depends on many factors, such as the actual enforcement effort, the initial speed and safety level and the type and amount of supporting publicity. In addition, not all evaluation studies take sufficient account of the regression-to-the-mean effect, which may lead to an overestimation of the effect.
It has been claimed that fixed, visible speed cameras may lead to dangerous traffic situations, because of sudden deceleration at the approach of a camera and acceleration after having passed it: 'the kangaroo effect'. While one can actually see this happen, so far there is no scientific proof that this leads to dangerous situations or accidents.
Reported effects of (generally hidden) mobile speed cameras range between 15 and 35% . The advantage of mobile cameras is that drivers are less aware where exactly they will be applied. The disadvantage is that they require more manpower.
Trajectory control is still very new, not yet widely applied and not yet evaluated on substantial scale. The first indications are very positive with hardly any speed violations left at the enforced section .
Factors increasing the effectiveness of national programmes of automatic enforcement include clear guidance on the criteria for enforcement sites, public information that maximises acceptability of the programme, and a short time interval between violation and fine to maximise the educational impact of the sanction .
At least in theory, non-automatic enforcement has three advantages compared to automatic enforcement. The advantages are related to the fact that violators are immediately stopped by the police:
- The violator receives immediate feedback
- The police officer has the opportunity to explain why they are enforcing speed
- If violators are stopped at a clearly visible spot, other drivers can see that the police is around and as such it increases the subjective chance of apprehension
The disadvantage is that non-automatic enforcement is far more labour-intensive and that it is virtually impossible to reach the same enforcement level as with automatic enforcement. Hence the objective chance of apprehension is much smaller. This is even more the case with non-automatic distance control than with non-automatic spot control. A police car that follows the traffic stream has a relatively small chance of detecting a speed violator and if so to follow that car for a sufficiently long time.
Essential elements for successful speed enforcement
Essential elements for successful speed enforcement are:
selection of roads or road sections with a safety problem related to speed
- A good organisational framework
- Enforcement level made dependent on observed speed/speeding levels
- Application of a combination of visible and hidden, fixed and mobile enforcement tools
And last but not least, a large amount of publicity on the enforcement project.
The role of publicity in enforcement initiatives
The effect of any speed enforcement initiative is substantially increased if it is supported by targeted information to the road user:
- Emphasising that safety is the goal of the enforcement activities
- Avoiding the appearance of collecting revenues to go to the national treasury
- Preferably illustrating that the revenues of fines are used for road safety purposes
- Providing feedback on the (interim) results of the enforcement activity (in terms of speed levels or safety)
Information at local or regional level is more effective than information on national level. The problem and the need to take action can be illustrated on the basis of examples that are known to the target drivers. Local newspapers, local radio or television and door-to-door leaflets are all suitable media for this purpose.
Drivers' opinions about and experience with speed enforcement?
European drivers are fairly positive about speed enforcement. However, they are more positive about drink driving enforcement. The SARTRE 3 survey  provides information:
On average around 60% of the drivers in the EU are (strongly) in favour of more severe penalties for speeding. With respect to drink driving approximately 85% are (strongly) in favour of more severe penalties.
On the other hand, European drivers think that they are more often checked for speeding than for drink driving. On average around 30% have the perception that on a typical journey they are often, very often or always checked for speeding, as compared to 10% for drink driving. There are huge differences between countries, in particular related to speeding. For example in Cyprus, Slovenia and the UK almost 40% of the drivers think they are (very) often or always checked on speeding, whereas in Sweden, Denmark and Italy this is around 5%.
Actual experience with speed and drink driving enforcement shows that penalties for speeding are far more common than for drink driving. On average, in the previous three years, almost 20% of the European drivers had been penalized for speeding as compared to less than 2% for drink driving. Clearly, this is not only related to the enforcement level, but certainly also to the frequency of both types of violations. With regard to speeding there are again large differences between countries. Drivers in the Netherlands are most often detected and penalized for a speed limit violation (46% in the last three years), followed by Germany (36%) and Slovenia and Austria (30%). Least often detected and penalized were drivers in Portugal (6%), France (8%) and Sweden and the UK (9%).
In particular for the UK, there is a remarkable difference between the subjective likelihood of being penalized for a speed limit violation (the UK belonging to the top 3) and the actual experience with speed penalties (the UK belonging to the bottom 3). This may be related to the large amount of publicity and discussions in the British media about the speed enforcement.