The essential difference between being careless with a gun in public and drunk driving on a private road is the matter of consent. You don’t have a right to risk strangers lives without their consent, but you choose to get on a road on which drunk driving is allowed. (Don’t forget that I am talking about private roads, which involve a consensual transaction every time you get on the road.)
You missed my point: I said that even if a road owner allows rights violations (to take it to the extreme) on his road, it is still not a valid contract between the drivers: if the road owner makes the rule of “on my road, folks, everyone is allowed to drive and shoot, (yee-ha)” and somebody kills/injures someone, they are guilty of murder or should pay compensations, regardless of the rules on that road.
So even if some rules can be regulated in private contracts, they should not be, IF they are violations of rights.
So the essential question is: Is drunken driving a violation of rights? If it is, it doesn’t matter who owns the road or what rules he decided on. If it is not, then the rules on that road determine what should be done.
I need to think more about why drunk driving (or driving under influence of drugs) is a violation of rights, but here are my arguments so far:
When heavily drunk, or under the influence of mind-altering drugs or drugs that cloud one’s judgement and ability to think/react, a person behind a wheel becomes the holder of a dangerous weapon, instead of a tool of transportation. The line that makes it a weapon instead of a tool of transportation is when the driver is unable to prevent accident in regular situations of driving a car (such as the ability to remain in one’s lane, to stop behind the car in front of you under some average (or “normal”) deceleration, ability to notice people who are crossing the road, etc’). When a person is unable to perform these tasks, they are operating a deadly weapon against other people: if someone will not be harmed by it, it would be a coincidence. It would be as if someone started shooting in a street in all direction (suppose he did it from a distance, with a silencer, to make it more like this case), and eventually hit no one. Did he initiate the use of force against people? Well duh. Even if he hit no one, or even intended to hit anyone, it doesn’t matter.
The relation, in the eyes of law, is between using a gun (in the way I have described) and the probable outcome, not between using a gun and actually hiting someone. And the heavily-drunk driver is just the same.