No time to look up and cite specific articals...

There was a freight train/bus full of kids accident...attributed to the train operator being high on weed. Thinking it was was 20 or so years ago.

I'm fuzzy on the specifics, so don't quote me.

MJ and driving...thats all about the sort of high the driver has. If they're couch lock behind the wheel...yea, prolly a bit lazy and not even doing the speed limit. When a mental buzz...senses hightend sort of thing....driving is flat out pleasurable.