EDIT: which is to say that cities can exist as the tax-generating powerhouses that they are _because_ they subsidize public transportation. That subsidized city transit is why we can afford to maintain the highway system.
I don't think this follows...
Cities that don't have good public transit still generate tax revenue.
It seems like a chicken-and-egg problem. Spending on public transit means there's budget for infrastructure. Highways being built means there's budget for infrastructure.
Budget for infrastructure means infrastructure gets built.
It seems almost... Tautological.
And just to be totally clear; right now no one is paying their fair share for driving, since no one pays a cent to cover their emissions. People who's home has a gasoline engine are just super-duper not paying their share.