Marijuana And Actual Driving Performance

U.S. Department of Transportation,
National Highway Traffic Safety Administration
(DOT HS 808 078), Final Report, November 1993

INTRODUCTION

This article describes the results of a research program that was set up to determine the dose-response relationship between marijuana and objectively and subjectively measured aspects of real world driving; and to determine whether it is possible to correlate driving performance impairment with plasma concentrations of the drug or a metabolite. The program consisted of three driving studies in which a variety of driving tasks were employed, including: maintenance of a constant speed and lateral position during uninterrupted highway travel, following a leading car with varying speed on a highway, and city driving. A laboratory study preceded the driving studies for identifying the highest THC dose to be administered in the subsequent studies.