EXECUTIVE SUMMARY

INTRODUCTION AND APPROACH

This is the final report of a project entitled "State of Knowledge of Drug-Impaired Driving." The project was conducted by Mid-America Research Institute, Inc., of New England for the National Highway Traffic Safety Administration (NHTSA). David Shinar of Ben Gurion University of the Negev, Israel, and J. Michael Walsh of The Walsh Group, Bethesda, Maryland, made significant contributions. This review examines research published during the 1981-2001 period and references some of the earlier material contained in prior reviews.

The scope of the review included foreign as well as U.S. literature with a direct bearing on highway safety. The review emphasizes controlled substances to include marijuana, benzodiazepines, non-benzodiazepine sedative and hypnotic drugs, and others such as amphetamines, cocaine, hallucinogens, and narcotic drugs. However, research related to any other drugs having the potential to significantly impair driving is also included in the review. Applicable research conducted in foreign countries, and documented in the English language, is included.

This report is presented in six substantive chapters. Chapter 2 contains a description of the methods followed in determining the topics and issues of concern in the review, identifying, acquiring and screening the documents to be reviewed, and reviewing individual documents. Chapter 3 deals with research pertinent to the detection and measurement of drugs in drivers, and Chapter 4 reviews the experimental literature, including research conducted in a laboratory testing human performance on tasks believed to be related to driving, and research conducted either in a driving simulator or on a closed course testing performance in actual driving tasks. In Chapter 5, we examine literature flowing from epidemiologic studies of drugs and traffic crashes, including literature on the drug use of various subgroups of drivers such as drivers arrested for drunk driving or "drugged" driving. Chapter 6 deals with literature on countermeasures for drug-impaired driving, and Chapter 7 presents our conclusions and recommendations. An index of terms and a bibliographic listing of references follow at the end of the report.

Our conclusions and recommendations are organized by the four major types of scientific literature examined in the review, namely:

The conclusions and recommendations are presented below. Examples of documents supporting the specific conclusions are cited, and cross references to pages of this report discussing more general conclusions are provided.

DETECTION AND MEASUREMENT OF DRUGS IN DRIVERS

Conclusions

Recommendations

EXPERIMENTAL RESEARCH

Selected literature on the effects of a wide range of drugs on performance of driving-related tasks and performance of actual driving tasks was reviewed. Classes of drugs considered were:

Conclusions

Recommendations

EPIDEMIOLOGIC RESEARCH

Conclusions

Recommendations

COUNTERMEASURES FOR DRUG-IMPAIRED DRIVING

Conclusions

Recommendations