Heavy users begin to experience paranoia which would explain instances of aggression. As far as driving stoned, it’s not a good idea. The actual act of driving itself isn’t so much the problem, since the fear of being stopped is enhanced. The problem is distractibility, fiddling with the music, talking, anything other than concentrating on driving. I can imagine crashes are more likely due to this distractibility. So many distractions behind the wheel nowadays.
Great point! That could definitely be a factor.