Note that almost all transportion is heavily subsidized. Cars are given a giant road and highway system, and free or cheap parking almost everywhere, plus laws requiring all builders to include such parking in all buildings. If gas taxes went to pay the true cost of this (and the cost to the atmosphere and planet) then we could say cars don’t get giant subsidies. (Some cars like the Prius get an extra subsidy, though it may simply compensate for burning less gas.)

Right now in most American cities, and even outside, transit is too often slower or less flexible or even more expensive than the perceived cost of driving (namely parking and gas) even for one person, and often for 2 or more. The main goal is to fix that where we can. I took the free streetcar on one of the spare the air days, but of course many still drove.