Question: How would roads be operated and financed in the ideal libertarian world? How would traffic violations, actions which may be victimless crimes but would be very likely to harm others if they were allowed to continue unchecked, be handled? 
Answer: Roads would probably be operated by companies which would finance them through tolls (highways), subscription fees (local roads), or measures similar to condominium dues (neighborhood streets). Even today, some communities finance almost half of their roadways through these alternatives, saving themselves up to 50% when compared to government-run alternatives.
Road owners would set the standards for drivers' conduct (e.g. speed limits, alcohol load, etc.). Reckless drivers, regardless of whether they were under the influence of mind-altering substances, would probably be banned by road owners so that customer safety could be maintained.
Libertarians believe that defensive force can be used against those who initiate or THREATEN to initiate force against others. Prohibiting reckless driving could certainly fall into that category.
