All government laws are worthless, even those against murder. You don’t stop certain phenomena by prohibiting them. Such are reduced naturally when conditions for maximizing utility are upheld. Outright bans merely create black markets. Even with murder. It is adequate self-defense of would-be victims, and not anti-murder laws, that stop would-be murderers.
But then, rules as decided by private property owners serve a purpose. Engaging in certain activities remains a matter of choice. For example, a restaurant owner may not permit smoking in his establishment, but you’re still free to do so in your property, or in that of another restaurant owner. No ‘black market’ for smoking emerges even if all restaurant owners do not allow smoking, because these owners, being profit-oriented, would merely be reflecting clients’ general sentiment against smoking. True democracy has nothing to do with government, and everything to do with private property.
Rules against drunk driving still impractical
I contend that even in a purely private system of transportation, where roads are controlled by actual owners, there would be little sense to impose rules against ‘drunk driving.’
It is the sober person who decides to drink on occasions where driving afterwards is likely. Rules that outline the consequences of being found liable for traffic accidents, should appeal to such a sober person, not to the future drunk person who couldn’t be expected to make good decisions.
A person, knowing the trouble associated with vehicular accidents, thus makes the decision, even before drinking, to drink less than he otherwise would without the limitations of being a driver.
To charge a person who could hold his liquor and drive safely is thus no precaution. Intoxication levels, if they can be measured so conveniently, may serve as guides for would-be drivers, but for these to be more than recommendatory would not make roads safer.