Driving Under the Influence of Cannabis: Impact of Combining Toxicology Testing with Field Sobriety Tests
Cannabis is increasingly used both med- ically and recreationally. With widespread use, there is growing concern about how to identify cannabis-im- paired drivers. A placebo-controlled randomized double- blinded protocol was conducted to study the effects of cannabis on driving performance. One hundred ninety-one participants were randomized to smoke ad li- bitum a cannabis cigarette containing placebo or delta- 9-tetrahydrocannabinol (THC) (5.9% or 13.4%). Blood, oral fluid (OF), and breath samples were collected along with longitudinal driving performance on a simula- tor (standard deviation of lateral position [SDLP] and car following [coherence]) over a 5-hour period. Law enforce- ment officers performed field sobriety tests (FSTs) to de- termine if participants were impaired.