With the car problem, no one entity has the power to devise nor enforce a holistic solution. Of course, with the exception of a fascist overthrow of the state that tears down cities and rebuilds with central planning. The government can't just come and take people's cars away – you have a right to own a car (more or less). You don't, however, have a right to a parking spot, and it takes just a small city committee meeting to affect change.
That's not to say people won't get hurt by this, but it needs to happen for the good of everyone. Suburbia is bad for the earth and everyone on it. We need to start making some tough decisions... 30 years ago.