Actually, public goods associated with automobile transportation - roads, traffic control, police protection, safety testing, etc. are already financed by government i.e. general taxes. The only difference is the point of collection, gasoline tax is collected at the pump while general taxes - from your mortgage payments or paychecks.
Given the mildly progressive nature of our tax system and essentially regressive nature of gasoline tax - this is not necessarily a bad thing. The same pertains to the various "user fees" proposed by some technofiles (e.g. electronically recorded fees for using specific roads or even lanes, sort of E-Z Pass writ large) - these fees would hit the communiting working class harder than the leisure class.
Another problem is no matter how expensive gasoline becomes, people will still drive instead of taking the bus. Main reasons are the lack of alternative means of transportation (except NYC and maybe Boston), and personal security (buses can be very rough places in most cities).
The only solution to discourage driving would be building a decent public rail-based (buses won't do because are inherently slow, since they do not have the exclusive right of way) transportation system and then incremental introduction of various incentives, such as "planned congestion" which involves restriction on automobile access and parking.
wojtek