Those exist all over the country. Here in Illinois, the state legislature solved that problem-- and it was a huge problem until they stepped in. State law capped the fines for speeding violations statewide at $75 (1-20 over) and $95 (21-30 over); the 'arresting' agency is entitled only to 50% of the fine is collected.
I doubt the law reduced the number of drivers speeding, but when it was passed (a long time ago), it did reduce the number of speeding tickets issued statewide, most markedly in a few downstate counties. Property taxes went up the next year in more than one downstate county that hadn't raised property taxes in a long time.
^ to the Illinois legislature. Now tickets are given for traffic safety purposes, not to generate revenue. Get pulled over in Wisconsin, however, and you could end up forking over $250++. Guess where the speed traps are now . . .
I have a solution as well: if the Attorney General for the state can show that ANY of your projected budget derives from anticipated fines, all persons involved will be charged with public corruption. In other words, if you have 100 police officers and 50 firefighters, you better be able to pay for it through normal tax revenue.