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.