In Japan you have to vouch that you have a parking space for your car. I think a similar rule would work for the states. However, it will cause a huge tension between the parking spot haves and parking spot have nots, without adequate equality will be seen (rightfully so) as a move to limit cars among those who can't afford parking spots for them.

For better or worse, the USA has basically made a contract with its people that "you have the right to a car, and because of that, we will provide really sucky public transit." That contract has to change before we start aggressively taking cars out of the system.

> if there's demand for residences with parking spaces, developers will build them

That's somewhat optimistic. In the absence of rules, developers will maximize their profit above all else. Apartment units are far more profitable than parking, so they'll just build the maximum units with no parking.

I lived in such a neighborhood once. Result is 50 unit buildings with 4 parking spots. And the result of that? People driving around the blocks for hours looking for parking, fights breaking out over parking, cars constantly vandalized for taking over "their" spot. It was not fun.

I mean, typically laws do not substitute for the creative process of designing and marketing buildings. What color should the walls be? What kind of kitchen faucet should you have? What should the countertops be made out of? What flooring surface will you use? There is no reason that "how many parking spaces should we build" be the 1 question that the government answers for you. Make an educated guess. If you're wrong and build too many, you leave money on the table. If you build too few, then people will buy some other unit with more parking.