As an example of stupidty a couple of years ago one of the reasons given for a budget short fall by our council was that they had allowed for the inclusion of £X00,000 per year for fines issued by the council for all sorts of infringements (not just parking). Due to an upsurge in lawfullness OR at least not catching people the fines generated a LOT less. Surely sense dictates that this sort of income is uncontrollable, so shouldn’t any revenues raised that way be used in a following financial year to prop the budget up? Or is that too logical? The same happens when parking fees are raised imposed. Costs as state4d are added anyway to raise the revenue and often the effect of charging is that people stop using the areas or at least find some where else to park for free.
But I’m a scientist/engineer not a financial wizard so maybe I’m simple.