Much of the progress that has been made in impaired driving in the last decade or more has been facilitated by lessons learned from other countries. It is therefore both timely and appropriate for the National Highway Traffic Safety Administration to sponsor a systematic effort to gather information about impaired driving around the world. In particular, this report summarizes information gathered on the measurement of alcohol involvement in countries around the world. This report is a follow-up to a previous phase of this effort. The report for that phase is entitled Literature Review of DWI Laws in Other Countries (NHTSA 2000). That project collected information on laws and policies related to drinking and driving in industrialized countries. The intent of this entire effort is to contribute to our understanding of impaired driving countermeasures and their impact and of how the current situation in the United States compares to other countries. The parameters of the report are described below.
The primary purpose of this project is to provide comparisons with the United States, and therefore possible guidance in the development and implementation of impaired driving policies in this country. Therefore, the main focus of data collection was on countries that would be considered most directly comparable to the United States, economically and demographically, as well as those countries with which we have the most direct dealings. These countries include:
Most of the information for this report was gathered through inquiries from key informants identified in each of the countries of interest. Most informants were from government transportation agencies. Some informants were from relevant university departments. In some cases, available information was collected from other published or unpublished sources. Appendix A indicates the source(s) of information for each country. Some countries did not respond despite repeated requests for information.
The results of the inquiry indicate that the definitions used in the United States to track alcohol involvement in fatal crashes are not shared by other developed countries. The initial goal of the project was to compare the rates of fatal crashes involving alcohol from country to country. It was hoped that information about variations in laws and policies could be correlated with variations in the alcohol involved crash rates and thus provide some guidance regarding the effectiveness of impaired driving countermeasures. It was found, however, that the data reporting and collection methodologies, definitions of alcohol involvement, and data reliability and validity were so variable as to make comparisons impossible. Several key issues were identified regarding data comparability. These include:
In addition to methodological and definitional differences, questions remain concerning the accuracy of reported rates in many countries.
Until a methodology can be developed to adjust for differences in reporting, meaningful comparisons of rates or conclusions about the effects of legal differences from country to country cannot be made.