I'm not sure how one might reliably assess/assert impairment for a cannabis user. Traces can last for weeks and result in positive tests (blood analysis), even if the user isn't remotely stoned at the time. Don't know whether there's a breath test nowadays that indicates use in the past n hours, which might give a better idea of likely impairment.
It's not an idea I've explored seriously in any depth, but it seems like testing for capabilities required for a specific task might be a way to go here over actual drug tests. Thus if it's determined that people need a certain reaction time to drive safely, that could be one thing tested. Clearly setting the levels and the particular capabilities might well be contentious, but by aligning the test(s) with what's nee…
from https://www.drugabuse.gov/publications/research-reports/mari...
I wonder how much marijuana actually contributes to crashes. I think people can certainly get too high to drive, but unlike alcohol which lowers inhibitions, being 'too high' could even increase inhibitions somewhat (more anxiety, paranoia), so I'd expect people too high to drive are much less likely to get behind the wheel than drunk people. I certainly buy that 0.1% BAC + marijuana is probably worse than 0.1% BAC alone, but I'm curious what a just legal limit would be in comparison to 0.08% BAC regulations. What BTHCC produces equivalent impairment to 0.08% BAC, and how does that interact with THC tolerance?
Are people who consume thc multiple times per day worse drivers than people who never consume thc, when both groups are sober? I'd imagine there is a tolerance effect where stoned frequent-users are better drivers than stoned infrequent-users.
Would be interesting to try to make a cabinet arcade-style driving game that would accurately predict actual-road driving ability. Could even be used as a tool to demonstrate the dangers of drunk driving by putting it into bars and letting people try when above the legal limit (definitely some dangers of giving people good scores when they perform well while drunk though...)