Cannabis Impaired Driving: An Evaluation of Current Modes of Detection

Abstract

Due to the growing concern with motorists driving under the influence of drugs, the Canadian government has recently implemented legislation to tackle this issue. The new legislation compels drivers to submit to a series of tests, by a police officer, if/when a motorist is suspected of drug impairment. The aim of this paper is to present a review of scientific studies that have evaluated the effectiveness of three methods to detect cannabis use in motorists. These methods include the Drug Evaluation and Classification (DEC) Program, on-site oral fluid screening devices, and on-site urine screening devices. Only studies that included appropriate measures of reliability (i.e., sensitivity, specificity, and accuracy) were included in this review. Given their increasing reliability, on-site oral fluid devices appear to show the most promise for the detection of cannabis use in motorists. Despite the promising results, however, there is still a need to establish standard levels of impairment for cannabis, like the blood alcohol content (BAC) cut-off levels for alcohol, before these devices can be meaningfully utilized and implemented.