When we find an open spot on the street, and there’s no meter, it seems free — but it too is the result of government spending. The cost of the land, pavement, street cleaning, and other services related to free parking spots come directly out of tax dollars (usually municipal or state funding sources). Each on-street parking space is estimated to cost around $1,750 to build and $400 to maintain annually.
Follow the link and you’ll learn that off-street surface parking can cost $1,500 to $2,000 per space. Underground parking, like the massive underground lots being dug out for new apartments all over Seattle, cost much more, on the order of $20,000 or more per space. That translates into higher construction costs, which means higher rents and less affordable housing.
The whole article is a fantastic primer on why free parking is so terrible. I want to quote the whole thing, but you should go read it instead.