Chapter 4: Alcohol and drug use (task 1)

Deliverable D3.1 of the EU FP6 project SafetyNet
Assum, T.; Holló, P.; Mathijssen, R.

Road safety can be assessed in terms of the social costs of crashes and injuries. However, simply counting crashes or injuries is an imperfect indicator of the level of road safety. When crashes occur it is the “worst case scenario” of insecure operational conditions of road traffic. Work Package 3 of SafetyNet deals with Safety Performance Indicators (SPIs). A Safety Performance Indicator is any variable, which is used in addition to the figures of crashes or injuries to measure changes in the operational conditions of road traffic.

SPIs can give a more complete picture of the level of road safety and can detect the emergence of problems at an early stage, before these problems result in crashes. They use qualitative and quantitative information to help determine a road safety programmes’ success in achieving its objectives.


One of the main goals of SafetyNet WP3 is to develop a uniform methodology for measuring a coherent set of safety performance indicators in each of the 25 Member States and some non-EU Members. This report provides the first ideas from the WP3 team on this subject.

The SafetyNet team will move on to the other goals (offering technical assistance to some Member States that fail in producing the SPI data according to the developed uniform methodology & collecting current data on SPIs that meet the standards of the uniform methodology) at a later stage in the project.

Research areas

Work Package 3 of SafetyNet investigates SPIs in seven different road safety areas.

  1. Alcohol & Drug use
  2. Speeds
  3. Protective systems
  4. Daytime Running Lights
  5. Vehicles
  6. Roads
  7. Trauma management

State of the art report

This report starts off with a description of the general methodology. Then, the report describes the state of the art in the seven research areas. Firstly, the theoretical backgrounds of each research area are given. Secondly, the first results from the questionnaire (that was sent to 27 countries: the 25 EU Member States, plus Switzerland and Norway) are presented. And thirdly, the first ideas on the details of the SPIs that could be used in the future are described.

Summary Task 1: Alcohol & Drug use (Chapter 4)

Driving under the influence of alcohol and drugs is one of the most important factors increasing the risk of severe road crashes because impaired road users are likely to be reckless and to behave inadequately when a dangerous situation appears. Moreover, impaired road users may also be more vulnerable to physical impacts caused by collision. Better knowledge of the prevalence of alcohol and drugs among road users will contribute to the understanding of crash risk and to the need for counteraction, such as legislation, enforcement, and information. Task 1 concerns the development of Safety Performance Indicators for the use of alcohol and drugs in road traffic.

Somewhat less than half of the 27 countries indicated that they have data on alcohol prevalence among injured or killed drivers, and 4-6 countries have data on drug prevalence for such drivers. Based on these data, a SPI is proposed: the percentage of road users involved in fatal crashes and impaired by alcohol or drugs.

Data should be collected from the remaining countries to check to what extent using of the proposed SPIs in the future is possible. A detailed protocol for the SPI still has to be elaborated.

Published in
State of the art Report on Road Safety Performance Indicators
SWOV (ed.)
European Commission, Brussels

SWOV publication

This is a publication by SWOV, or that SWOV has contributed to.