For now, let me cover just one aspect of legalization: the issue of roadside testing for marijuana impairment. There seems to be a widespread assumption that because the law permits on-the-spot testing for impairment, such testing must be a practically possible thing; a solved problem. There is no shortage of hustling inventors of roadside measurement devices for tetrahydrocannabinol (THC), pot’s main mind-altering ingredient, in saliva. “Oral fluid” (OF) testing is agreed to be the best chance for a practical breathalyzer-type device to test for drug impairment. So far there are only the faintest signs of trouble from the U.S. states where recreational pot is legal.

Source: National Post April 21, 2017 18:45 UTC