Comparing the UK and the US here is absurd. I live in the UK too and pratically speaking marijiuana is decriminalized. The police do not prosecute ordinary users and "small time growing" is often a warning or a fine.

Compare that to america where a tremendous number of college-age kids are imprisoned, where vast swathes of the black population are put away, where police meet their targets for funding by prosecuting weed smokers. It's a completely different world.

The "drug driving" is not being legalized anywhere. Illegal things are still illegal. "Mindless paranoia caused violence" is, as far as any one can tell, a myth. But even so, that's a HEALTH issue - not solvable by police.

As for "negative effects on society" and "health care budget" - these are phrases meant to restrict lifestyles available to people on the basis of your own fear, self-interest and jealousy. "Freedom" if it is to mean anything is the ability to enjoy: to have your life be - to you - enjoyable and worth living.