Then create public transit districts, which operate like school districts. Real estate is taxed, and the proceeds go to busses.
Areas with high real estate values will have excellent public transit. Those with lower real estate values will have worse transit.
The advantage is (1) support by middle and upper class voters, who are traditionally opposed to public transit, (2) funding sustainability, (3) money is kept in local communities.
The downside is a drastic increase in inequality.
I’m obviously joking … but do you see how discouraging cars would increase inequality unless it was combine with an extremely equitable political system? A political system America doesn’t have?