I agree with AKSAR about cuts in maintenance, although I am clearly biased. When it is time to cut the budget, routine maintenance is often first on the chopping block. You can get away with that game for a little while, but it will eventually come back to bite you. Responsibility for highway maintenance varies with each park - sometimes it is the park itself, and sometimes it is the state or county, etc.

One thing to keep in mind about money spent to run and maintain National Parks, is that many parks generate work and jobs in the surrounding area. Several states offered to provide the money to run several parks during the recent shutdown. They weren't being philanthropic - it was just good business.