While I fully support taxing the crap out of cars, Singapore and the USA are hardly comparable. It's the third most densely populated country on earth, and you can walk the circumference of the entire island in about a day. Not even factoring in the comprehensive public transit..
This can't be stressed enough. Large swaths of the US population would immediately become immobile. I think OP has never lived and worked in a rural area, say 30 miles outside of the nearest town, where survival depends on your ability to transport yourself.
In a way, the invention of the automobile made our lives worse. It meant grocery stores and services could be placed further and further away, stretching out areas rather than condensing them.
