A very good point, in fact a lot of semis have provision for 3 or 4 cars (1 in garage, 2 on driveway, 1 on street), and have 3 or 4 cars - the poeple opposite me certainly do, while in the terraces on my side we are restricted by only having on-street parking and only have 1 car per house. Therefore the logical way to reduce car ownership would be to only build new houses without driveways so they only have the 1 on-street space and stop people turning front gardens into more driveway.
As for subsidised parking spaces, if residents were charged a going rate for the space, then everyone else who parks on any public road for any length of time would also have to be charged. On my street, peak parking time is not at night when the residents cars are parked, but during daytime when people are visiting the local hospital or the church. Surely they should pay if we do? And then there's the people stopping to visit the bank or the local shops. They'll all have to pay just to make things fair, although it'll kill off the local shops.