Another option is a tax on miles driven, or perhaps a higher tax only on miles driven without any passengers. That way, one can ride wherever for free but when

Another option is a tax on miles driven, or perhaps a higher tax only on miles driven without any passengers. That way, one can ride wherever for free but when sending the car out by itself, it'd cost enough to discourage such behavior. In fact, this latter option is almost a given, IMO, not only to reduce congestion but also energy use (even if the cars are not running on fossil fuels). Some incentives for city parking garages to make them cheaper would also help. There's absolutely no need whatsoever for anyone to send their car back home just to get it parked when there's guaranteed parking within a couple of miles, only a few minutes away for the car.