I believe paranoia, to an extent, plays a part in our safe driving, after smoking. Now, if everyone was stoned, maybe it'd be a different scene on the roadways. That would erase any aggressiveness, or, road rage.

Also, whenever you hit the road, there's a chance that you'll see a cop, and, driving with a cop in one of your mirrors makes you triple your concentration, then you're paranoid that you won't have the mental capacity to talk to yourself, or someone else in the car.