Here in Colorado it's called DUID, or driving under the influence of drugs; ANY drugs that hinder your ability to drive, be it weed, xanax, oxycontin or what the Fuck ever. Fines, jail, revocation, classes, the whole bit. I'm not proud to say I do have a DUI and my classes started filling up with kids caught driving while high and one or two had an accident while on prescription drugs.
I hear all the arguments about tolerance, etc and the older I get, the more I feel lucky I survived such stupidity- and even more fortunate that I didn't hurt anyone else.
Driving is inherently dangerous enough as it is, made more so by the fact that we do it so much it becomes routine and yes, even boring.
Youth loves to say, "that won't happen!" Age has seen it. Now y'all know why old people drive so damn slow!
Put your weed in the back and smoke it when you get home. That way, if/when you get pulled over you can tell the officer that yes, you have marijuana in the car, but it's in the trunk- and he'll be like, 'cool'- even if he still has to write you a ticket.