Actually I think this'd be a recipe for scams to proliferate. Law enforcement processes mostly occur after the fact, often long after, and in any case, a great many nations already do take consumer choice seriously.

The transportation metaphor is somewhat problematic, because roads are commissioned and paid for by the same class of agency that employs traffic enforcement officers: domestic government. Nevertheless, delegating the enforcement of regulations to an accountable private entity is a common practice, and you'll see it in everything from medicine to logistics.