I always thought an annual pass/day pass system for the park would be well worth it to get the funding up to support a larger ranger force. I know a friend lost her job as a ranger on the NC side last year due to budget cuts.
Donations and federal money is just not cutting it, I would fully support a paid entry fee to use the park to keep the rules enforced and the park pristine. I would also expect more than traffic enforcement from this type of approach though. If they just doubled the amount of speeding ticket writers, that would be a waste.