Why not reduce the burden on the system by banning alcohol? If you know the answer to that one, you know the answer to your own question.
I am not arguing the WOD or prohibition, the topic is traffic safety and the effects of pot on the ability to drive.
My point is that the legalization of another intoxicant would be likely to cause an increase in that ER load, so why go there.
Keep in mind that that increase in ER patients, whether for testing or for trauma will be utilizing resources already sorely taxed in some areas.
Why, with knowledge and forethought, increase that load by legalizing another substance which would have to be regulated, tested for, etc.?
There are those who will argue that the DUI industry is already one which has surpassed mere traffic safety and become a cash cow for certain sectors, namely law enforcement, local courts, and the evaluation, treatment, and rehab industry. There are others who will argue that it has become an excuse to set up checkpoints and violate the 4th amendent rights of Americans en masse. Why add another reason?