High on the highway—stoned-driving on the increase
October 26, 2018, De Gruyter
Getting behind the wheel after cannabis use is on the rise in the US, and THC, not alcohol, is now the most commonly detected intoxicant in US drivers. Detecting levels of THC, however, is challenging and the methods used so far cannot accurately determine a person's level of impairment.
The article "Driving While Stoned: Issues and Policy Options" by Mark A.R. Kleiman, Tyler Jones, Celeste J. Miller, and Ross Halperin, published in De Gruyter's Journal of Drug Policy Analysis, looks at current issues associated with cannabis intoxication when driving and the options available in testing for THC levels.
The study suggests that, due to the recent legalization of the production and sale of cannabis in some US States, the number of people driving under the influence of cannabis is likely to rise, which is unsettling since there is a widespread belief among marijuana users that THC does not have an effect on driving. Americans now spend an estimated 15 billion hours under the influence of cannabis per year, with no sign of consumption slowing down soon.
https://medicalxpress.com/news/2018-10-high-highwaystoned-driving.html
