I certainly would agree that people ought to be sober when they are driving. However, there just isn’t any real evidence that pot has any big negative effect on driving for experienced users. (New users are another matter, but I would guess that, for various reasons, there aren’t a lot of stoned new users on the road at any given time.)
For example, the US Government’s own studies indicate that marijuana is only a very minor part of the overall road problem, if that. Alcohol gets credit for about half of all the deaths, and all the illegal drugs combined don’t come close to that total. Never have and never will – just because of the difference in the effects on people. Most of those drugs – marijuana included – don’t impair physical coordination like alcohol does.
Some research from Australia and the Netherlands indicates that (experienced) stoned drivers may be safer, on average, than straight drivers. They figure this is not because marijuana is not intoxicating (it clearly is), but that the effects related to driving are not severe and the users are able to compensate for them. In fact, it would appear that they overcompensate and tend to drive more carefully as a result. (Not that this is a recommendation for driving while stoned – just that I am indicating the real results of research.)
In 1980, Road and Track did an article titled “Puff the Dangerous Driver” in which they attempted to show the dangerous effects of driving while stoned on pot. They took two groups of drivers. One group got increasing doses of alcohol, while the other got increasing doses of pot. Then they put them through a driving course. The alcohol drinkers’ driving rapidly went to hell. However, the pot smokers got gradually better at the course.
I don’t think 190 proof is allowed in all jurisdictions. The highest I have ever seen in California is 151 but then I don’t frequent bars and liquor stores very much, being the sober person that I am.
If it is decriminalized to that point, then what would be the point in having any penalty at all – other than to perhaps keep the black market alive?
Just FYI, in the US Government’s own surveys, kids commonly report that it is easier to get illegal drugs than the legal ones. This was the same condition with alcohol during alcohol prohibition. That indicates to me that we do better when we know who the sellers are and can license them and somewhat control their behavior.
See the note above about the relative hazards on the road. While this may be a logical worry, there isn’t any evidence to support the idea that legalizing marijuana would have much effect one way or the other.
Driving while impaired would always be illegal no matter what the laws, anyway – just like with alcohol, which you can get anywhere and is a far bigger problem on the road than any of the illegal drugs.