Reports



Police enforcement strategies to reduce traffic casualties in Europe


Executive Summary

Full report (.pdf format)

Introduction

The number of road fatalities in the fifteen countries of the European Union was about 42,500 in 1996. The total number of injured people annually is about 3.5 million taking under-reporting into account. In all EU countries, road collisions are the main cause of death for those aged 45 years and below. The total socio-economic cost of road crashes is around 160 billion euro. A large proportion of these crashes were preceded by one or more traffic offences and, on an aggregate level, traffic offences are the major contributory factor to road crashes and injuries.

Yet, in comparison with other types of road safety activity, relatively little is being done to prevent road users from committing offences. In view of the many other pressing problems facing police forces, road traffic regulation enforcement typically has low priority. While traffic levels continue to rise, several European countries appear to be devoting fewer resources to traffic policing than they were several years ago.

In some cases, the scarce resources allocated are not always used optimally. Much of the knowledge that has been gained through enforcement experiments and demonstration projects carried out over the years has yet not been translated generally into strategies that effectively change road user behaviour, reduce crash risk or reduce injury severity. On the other hand, there is evidence of demonstrably effective policing activity which, if pursued more widely across Europe, could contribute significantly to casualty reduction. A very substantial safety benefit would be achieved if road users were to be deterred from committing traffic law offences. Estimates vary, but it seems reasonable to assume that the magnitude of potential crash savings would be in the order of 50 per cent.

The aim of this ETSC review which has been prepared by experts from across the European Union is to focus attention on the importance of this area of road safety work, to highlight successful strategies and cost-effective enforcement methods and to make recommendations for action at local, national and international levels. A recent study of EU driver opinion found that 70 per cent were in favour of more traffic regulation enforcement being carried out.

The review includes discussion of the key traffic offences which are important for road safety and which need to be targeted in enforcement strategies. This goes beyond the enforcement of speed, alcohol and seat belt offences. Enforcement is not a stand-alone activity. There is ample evidence that enforcement is much more effective if it forms part of a systematic approach to road safety and is backed up by information and engineering measures. There is a large body of information to confirm that traffic regulation enforcement can be highly cost-effective.

What is the purpose of traffic regulation enforcement?

The main objective of traffic regulation enforcement is road safety – achieved by deterring road users from committing offences which are related to road crashes and injuries. It is not to maximise the number of infringement notices issued. Many enforcement activities are still too often directed towards detecting and apprehending the offending driver. Police activities should primarily serve as deterrence for drivers inclined to commit traffic offences through increasing road users’ perception of the risk of being caught. Consistent deterrence strategies, which typically comprise highly visible police or camera activity can bring about lasting changes in road user behaviour and, as a consequence, changes in road users’ attitudes which reinforce these behavioural changes.

Excess speed

Excess speed is by far the most frequent road traffic offence. The problem of excess and inappropriate speed is the most common and the most severe road safety problem. Both crash frequency and crash severity increase as driving speed increases. The potential for reducing crash injury, and particularly fatal injury, is substantial. On average, a 4 per cent reduction in crashes is estimated to occur for every 1 km/h decrease in average speed. The benefits are particularly high where vulnerable road users are involved: the probability of a pedestrian fatality reduces from 85 per cent at 50 km/h to less than 10 percent at 30 km/h.

Traditionally, two types of operational policing methods have been used to reduce speeding, but only one of them has proved to be effective in influencing behaviour and crashes. The stationary method generally involves an observation unit, typically an unmarked police car more or less hidden at the roadside, and an apprehension unit comprising one or more marked police cars, clearly visible, at which point speeding drivers are stopped. Mobile methods are defined as enforcement of traffic behaviour, and apprehension of individual offenders from a moving unmarked or marked car. Studies that have evaluated experiments with mobile enforcement only, indicate that mobile methods neither have any lasting, measurable effect on speed behaviour, nor on speed-related crashes. Even though it cannot be ruled out that mobile enforcement may have effects on other types of driver behaviour, such as drunken driving, research results clearly indicated that this method is not effective for speed enforcement.

In a recent analysis of 16 studies in which stationary speed enforcement was used alone or in combination with other enforcement methods, the average overall effect was estimated to be a 6 per cent reduction in casualties and a 14 per cent reduction in fatal crashes. Several studies have estimated the benefit-to-cost ratio of stationary speed enforcement to be between 3 and 12. Speed enforcement needs to be prolonged and intensive to obtain optimal effects.

In recent years speed camera technology has been used very cost-effectively. A recent analysis of 11 studies evaluating the effects of speed cameras found an average reduction of 19 per cent in the number of casualties. The reductions were found to be larger in urban areas (28 per cent) than in rural areas (4 per cent). Cost benefit analysis in one Member State found that the investment in speed camera technology generated a return of 5 times the amount after 1 year and more than 25 times the amount after 5 years. Where used widely, public response is favourable. The brother that is watching you seems to be preferred to the brother that may be killing you.

For the future, the possibilities of employing intelligent speed adapters (ISA) are now being explored in several EU countries.

Alcohol

While drink driving is relatively infrequent, compared to other traffic offences, it is highly dangerous. For the EU as a whole a rough average of about 3 per cent of journeys are associated with an illegal BAC, but about 30 per cent of injured drivers are under the influence of alcohol. Alcohol is one of the major causes of crashes and can increase the severity of injury outcomes.

A package of measures is needed in any strategy to reduce casualties in alcohol related crashes. First, the BAC-limit must be set at a level that gives clear guidance to drivers about safe driving practice. Accident analysis supports a limit of 0.5 mg/mlfor the general driving population. Experience shows that lowering the BAC-limit to 0.5 mg/ml has a positive effect on the offence rate as well as on injuries due to road crashes. This is a necessary basis for safety campaigns that set out to explain the regulations in order to influence attitudes. Police enforcement and penalties are concomitant elements.

The key to successful enforcement strategies to reduce alcohol-related casualties is to increase drivers’ perception of the probability of detection through programmes that involve the following:

  1. A high number of persons tested (at least one in ten drivers every year, one in three drivers if possible, as in Finland). This can only be achieved through wide-scale application of random breath testing and evidential breath testing,
  2. enforcement that is unpredictable in terms of time and place, deployed in a widespread manner to ensure broad coverage of the road network and difficult (for drivers) to avoid when encountered and
  3. highly visible police operations. Targeted policing can be employed to maximise apprehension of persistent offenders. For apprehended drivers, remedial treatment can be offered as an alternative to traditional penalties to reduce recidivism.

Enforcement needs to be accompanied by publicity in order to inform drivers and provide them with feedback. This serves to increase public acceptance of enforcement activity and reduce public acceptance of drinking driving. The development and consistent application of such enforcement and publicity activities has been carried out notably in Finland where the number of excess alcohol offenders has fallen during the past ten years from 33 to 14 per 1000 tested drivers.

Drugs and fatigue

There is a case for defining procedures for detecting driver impairment not only in relation to alcohol but also for fatigue and certain types of drug use. Whilst EU regulations for professional drivers exist defining combinations of driving, working, resting and sleeping hours are permitted, they need to be more sensitive to safety needs. These regulations are also widely flouted. The problem of driving fatigue needs to be addressed for the general driving population.

At the moment, the relationship between drug usage and crash involvement is still largely unclear. Enforcement strategies that can have an impact on drug usage in traffic still have to be developed. As the use of illicit drugs is ingrained in general lifestyles, incidental enforcement is unlikely to have a preventative effect through increased subjective probability of detection. For prescription drugs, preventative effects are more likely achieved through detailed information to the users.

Seat belt use

Seat belt wearing is mandatory (through EU Directive) in the front and rear seats of passenger cars in European countries. However, in spite of this legislation, usage levels vary widely from one country to the next. About 75-80 per cent of EU passenger car drivers reported using seat belt in the front seats in 1996. In most countries rear seat belt use was substantially less. If every car occupant had used existing seat belts that year about 10,000 of a total of 25,000 killed car occupants in EU would have survived. About 7,000 lives could have been saved had all wearing levels been up to the best achieved internationally.

Many studies show that enforcement increases seat belt use when combined with other activities such as information campaigns. The best way of achieving increases currently is through intensive, highly visible and well publicised enforcement. So-called ‘blitz’ approaches have been shown to be extremely effective in producing sharp increases in seat belt use. If such ‘blitz’ enforcement, usually lasting only one to four weeks, is repeated several times a year, high levels of wearing rates can be maintained. The STEP enforcement and publicity campaigns carried out in Canada have also been shown to be most effective. Several studies have estimated that the benefit-to-cost ratio of such seat belt enforcement programmes is of the order of 3 or above.

Alternatively, incentive programmes have been devised in which seat belt use is monitored and seat belt wearers are eligible for a reward – ranging from a free hamburger voucher to a lottery ticket for sizeable rewards such as video recorders or free holidays. In general, these incentive programmes appear to be very effective.

Ultimately, technological solutions will be able to reach the last 10-20 per cent of unbelted occupants who cannot be reached by other means. Intelligent warning systems when the belts are not used provide an acceptable and sufficiently effective method if the warning is made sufficiently aggressive, according to Swedish studies.

Priority or "right of way" offences

Failure to observe red lights or pedestrian crossing lights is a major safety issue in urban areas. The same applies to offences which involve failure to observe the priority or right of way of other road users, which comprise about half of the road collisions in urban areas. However, little enforcement effort is devoted to these types of offences. The same observation applies to offences such as use of restricted lanes, making U-turns or turning left or right where prohibited or overtaking in chevron-indicated areas. All these types of behaviour emerge as disproportionately risky in crash analysis but are rarely the targets of systematic enforcement.

However, camera technology is being used increasingly and very cost-effectively to prevent red light running amongst car drivers. Cost benefit analysis of red light camera operation in one Member State indicates that the return was nearly twice the investment after one year and twelve times this by year five.

Future trends

Traffic regulation enforcement has mostly concentrated to date on the important problems of speeding, alcohol impairment and failure to use seat belts. At the same time, there are other important offences in road safety terms which have yet to be included as priority areas in police work. For example, errors in overtaking or overtaking offences result in very serious crashes. Failure to observe red lights or pedestrian lights is a major safety issue in urban areas. Maintaining short distances (tailgating) substantially increases the risk of rear-end collision. All these types of behaviour appears disproportionately risky but are rarely the target of systematic enforcement. Aggressive driving is a major source of irritation amongst road users. Only when the scope of enforcement is widened to include these offences will the road user be made aware that it not acceptable to violate regulations whatever they concern.

The effectiveness of traffic law enforcement is dependent on the efficiency of the legal system. Traffic law is in most countries part of criminal law. While this may be appropriate for serious offences it is hardly possible to process the myriad of offences without making an exceptional demand on policing manpower or ‘clogging up the courts’. In several EU countries, the processing of offences is brought under civic or administrative law in order to increase the efficacy of the law enforcement system.

In several EU countries automatic detection and registration is used for offences such as speeding and red light running. These approaches are very cost-effective and will need to be widely adopted in traffic regulation enforcement strategies.

A further step is to build such devices into the vehicle. A number of EU projects have demonstrated that this is feasible and can apply to a wider range of offences than is achievable through roadside enforcement.

Further developments can incorporate in-vehicle devices that are "aware" of temporary road conditions or driver impairment. These developments will require strategic changes in enforcement policies and judiciary procedures once road user acceptance is assured.

Proposals for effective traffic law enforcement in EU countries

While traffic regulation enforcement is a matter for Member States, the EU can play an important role in its road safety programme in encouraging information exchange on effective strategies, disseminating research-based information in EU programmes and carrying out new research. The following recommendations are made, in particular, for action by those responsible for defining, promoting and implementing enforcement strategy at local, national and EU levels.

  • On the basis of detailed crash data analysis, set specific targets nationally for compliance with key traffic offences which influence road safety levels – the arrangements for doing so will vary from country to another. These targets specify the offences to be enforced and the acceptable compliance level for each offence after enforcement in quantitative terms (for example, 95 per cent seat belt use). These offences include, as a minimum, the general target behaviours (speed, drinking-driving, and seat belt use) but also other safety-relevant offences relevant for the country.
  • For each offence, integrate police enforcement activities into the national traffic safety policy relevant to that offence, at least including publicity activities.
  • In each country formulate for each offence, effective and feasible police enforcement strategies. These strategies should take into account the results achieved in experimental or demonstration projects carried out elsewhere, specify the means and methods of police enforcement and specify the allocation of resources. Increase effectiveness of detection by allowing random breath testing and camera evidence for offences such as speeding, red light violations and tailgating.
  • In each country identify offences that could be dealt with under administrative or civil law rather than criminal law.
  • Develop information and training resources in order to increase awareness and competence of police enforcement staff.
  • Obtain explicit agreements between the various actors (legislators, police, prosecuting bodies) about the consequences that follow detection of offenders.
  • As part of the EU road safety information system, communicate the results of specific demonstration projects amongst policymakers and police.
  • Encourage and support the establishment of an effective network of traffic police in Europe
  • As part of the Fifth Framework Programme, set up an EU-wide monitoring project to allow objective comparison of the incidence of specific offences and the incidence of crashes related to these offences.

Acknowledgements

ETSC gratefully acknowledges the contributions of members of ETSC’s Traffic Regulation Enforcement Working Party to this review:

Members

Prof. Talib Rothengatter (Chairman)
Dr. Ray Fuller
Dr. Charles Goldenbeld
Ms. Marie-Chantal Jayet
Dr. Tapani Mäkinen
Dr. Göran Nilsson
Mr. Allan Quimby
Dr. Stefan Siegrist
Dr. Hans Utzelmann
Mr. Truls Vaa

ETSC staff:

Mrs Jeanne Breen
Ms. Marie Ward

ETSC is grateful for the financial support provided by DGVII of the European Commission and for the contribution towards the printing and dissemination costs of this review provided by 3M Europe, Ford Europe, BP, and KeyMed The contents of this review are the sole responsibility of ETSC and do not necessarily reflect the views of sponsors nor organisations to which research staff participating in the Working Party belong.