there is almost no way a police department as currently structured can make a profit... well maybe in extremely rural areas with little crime.
tell me how much it costs to run a homicide investigation, with detective overtime, gas for duty vehicles, forensics tests, sheltering witnesses, etc etc etc. or rape investigations, and how many of those does a big city operate in a year? there's no way you can write enough traffic tickets to cover that.
the point of citations is to punish people for unsafely operating a vehicle, not to make profit for the citing agency. Seattle police for instance has a total budget of 268 million dollars a year. you won't be making enough profit in any way for that to be possible.
Ever noticed how some "non-profit" corporations are managed very much like for-profit companies? Due to the incentive structures in place, there is very little difference between a "non-profit" and a for-profit company. Both are managed by professional individuals whose salary may grow with success. The company's status as "non-profit" or "for-profit" reflects only whether there are owners who make a return from profits, and has essentially nothing to do with the management structure or incentives in place.
Similarly, whether there are owners who make a profit simply for holding title or stock, or a community who ostensibly owns the department, the actual decisions are made by professionals who take home a tidy sum.
You act as though these expenses mean the officers all hold other jobs and literally donate time and money to ensure the police stay on the beat. In doing so you completely ignore the large quantities of subsidies police receive from federal and state taxes (income, property, and other).
By your argument, there's no way prisons could ever be run by for-profit companies, because they have to rely on tax dollars to pay for all their expenses.