Depends, but if the rates are set properly, perhaps the market would take care of this problem.
Assume that the first half hour costs twenty five cents, the second half hour fifty cents, the third $1 and the fourth $2 and the fifth $2 and so forth. So two hours costs $3.75 but three hours costs $7.75. However if someone needs to stay that time, they would pay it. However if they needed to continue parking in the area they could move their vehicle, churning would take place, and they would save a considerable amount of money.
Preventing meter feeding is difficult without a bit of technology in place. If you have a sensor in the street connected to the meter, then there is no problem. If the time allotted is two hours and the car is there two hours and a minute, the meter goes into alarm and cannot be reset until the vehicle is moved. This also prevents piggybacking on someone else’s payment.
The issue, of course is usually “I don’t know how long I’ll be” so a parker puts in the maximum allowed for self protection. This isn’t really fair, but it’s how the system works. Pay by Cell Phone helps, as do systems that allow a “credit” to be issued if a driver leaves before the amount of time purchased is up.
My feeling is that the more flexible the system is, the more choices a parker has, the better. In the long run, people will be more favorable to rate increases if they understand that they aren’t being ripped off and that the system will react favorably to their needs.