I think there should be more False Alarms in the game, as I do believe there are plenty of false alarms, not just for Fire but Ambulance and Police, call examples would be:
School/Uni/College: Fire Alarm System (In the UK these are all connected to the fire service so vehicles are dispatched immediately and 99% of the time its a false alarm), you could even have University Halls as I'm sure my halls were hooked straight to the fire service.
I'm sure there will be other building hooked straight up to the Fire Service possibly government buildings, large train stations, Airport Terminals?
Person Not Responding (On Phone)(This could be an ambulance call).
Again with police, person not responding on phone line (I'm not sure if they are dispatched for this call, I'm sure someone will be able to tell us?).
I'm sure there are a lot more false alarms or calls with no outcome that services respond to, this would make the game more realistic and more challenging as units get tied up on these calls.
I'm not really sure but list calls below if you know more?