As others have pointed out: Parks already have patchwork fees, lotteries, and day-pass limits. This would just be a more holistic version of that patchwork. As

As others have pointed out: Parks already have patchwork fees, lotteries, and day-pass limits. This would just be a more holistic version of that patchwork. As far as "whenever I want it" public access, I think that most parks, and even some parts of every park, would be open to car traffic. So if you're willing to pay with your time, under this system (same as under the current system), you can go whenever.