The effect of the law is two fold, because it create the seen harassment of everyone for the supposed benefit of everyone but can hardly effect deterrence, yet people have a valid reason for siding with the law, being the belief/promise that this will stop, prevent even, or mitigate drunk people who endanger or harm others, and they helplessly rely on this mechanism to effect the change that should be effected by common sense at the opportune time and place, by them or others who have that concern, or stopping people from driving drunk and generally endangering others, which they won't go out of their way to stop, or tell a stranger to park it, let alone attempt to stop them.