Electric cars seem to be a pretty good solution, though the cars of the future will probably be much smaller - right now we pad them a lot with extra metal and plastic so that the passengers can survive a collision. With self-driving cars you won't need that anymore. I imagine the future of cars is a PRT[0] system - it's a perfect thing for a city. As for travel between cities, that's what trains are for.

[0] - https://en.wikipedia.org/wiki/Personal_rapid_transit