This report has been developed by the Department of Transportation in response to Section 212 of Title 11 of the Surface Transportation Act of 1978 (the Highway Safety Act of 1978). This section requires the Secretary of Transportation to report to Congress concerning efforts to detect and prevent marijuana and other drug use by motor vehicle operators. The full report is organized into five chapters: I. An introduction providing a brief history of the report, and a discussion of the similarities and differences between alcohol and drugs as they relate to highway safety; II. The frequency of drug use among drivers and its relation to highway safety; III. The legal approaches to the control of drug use by drivers; IV .Federal and State activity in the detection and prevention of inappropriate drug use by drivers; V. The Secretary's conclusions, recommendations and DOT programmatic actions.

This volume contains the papers and discussions from a Symposium on :'Hu man Behavior and Traffic Safety" held at the General Motors Research Labora tories on September 23-25, 1984. This Symposium was the twenty-ninth in an annual series sponsored by the Research Laboratories. Initiated in 1957, these symposia have as their objective the promotion of the interchange of knowledge among specialists from many allied disciplines in rapidly developing or chang ing areas of science or technology. Attendees characteristically represent the aca demic, government, and industrial institutions that are noted for their ongoing activities in the particular area of interest. of this Symposium was to focus on the role of human behavior The objective in traffic safety. In this regard, a clear distinction is drawn between, on the one hand, "human behavior," and on the other "human performance." Human per formance at the driving task, or what the driver can do, has been the subject of much research reported in the technical literature. Although clearly of some rel evance, questions of performance do not appear to be central to most traffic crashes. Of much more central importance is human behavior, or what the driver in fact does. This is much more difficult to determine, and is the subject of the Symposium.