Just reading your response to Frum's scaremongering on legalized weed.  When it comes to driving while high, I completely agree that there needs to be legal enforcement in place similar to drunk driving.  I don't want anyone on the road to be inebriated in any way.  But I'm willing to bet that the threat of hordes of stoned drivers as a result of legalization is misplaced.  People drive drunk because they're out for drinks and need to get home.  The majority of those who get caught DUI likely aren't plastered.  Sometimes they probably just don't want to pay for a cab and don't want the hassle of coming back to get their car the next day or whatever, so they decide to run the gauntlet and get caught. And good, because I don't want drunk drivers on the road.