Legalization of Marijuana Raises Need for Testing to Detect Impaired Drivers

By Lori Solomon, Editor, Diagnostic Testing & Emerging Technologies

With the movement to legalize marijuana use for medical and/or recreational purposes gaining traction, states are calling for improved standards for marijuana testing, particularly as it relates to measuring drivers’ drug-related impairment. But, the association between legal definitions of detection and the capabilities of tests to judge impairment is complex and not fully understood.

The Governors Highway Safety Association (GHSA) released its Drug-Impaired Driving: A Guide for What States Can Do report last fall. It provided recommendations that states focus on efforts to improve testing, including testing all fatally injured drivers, standardizing testing protocols and procedures for roadside testing and laboratory testing, and validating roadside testing devices. These efforts, GHSA says, will need to be informed by further research on the effects of drugs on driving; the effectiveness of drugged driving per se laws; the accuracy, reliability and cost-effectiveness of drug detection tests; and the feasibility of establishing national standards for various controlled substances involved in drug-impaired driving.

“An accurate, reliable, and inexpensive oral fluid test device that could be used at the roadside would be very useful. It should be quick and easy to use and should detect the most common drugs that impair drivers,” writes GHSA in its report. “If an oral fluid test were of evidential quality for some drugs it might reduce the need for blood tests. Research is needed to continue refining, evaluating, and eventually establishing standards for oral fluid test devices. Continuing research is [also] needed to determine if a useful marijuana breath test device can be developed.”

For further discussion of marijuana testing and need to provide law enforcement with tools that can help identify marijuana-impaired drivers, see “Inside the Diagnostics Industry” in the May 2016 issue of Diagnostic Testing and Emerging Technologies.