Traffic jam: the infrastructure may eventually change. Have a first car drive to to a nearby train or subway station, and a second car to your destination from the train. In the meantime, you may have more traffic jam.
Energy: when you don't need to own your car, you can use the best car for the job. A commuting car doesn't need to be able to carry 5 people around. It can be much smaller. Again, the transition period likely won't look good.
Harsher economic times: this is good old technological employment, where productivity rises faster than demand. My 2 cents: self-driving cars will significantly contribute to technological unemployment, and that's good, provided we manage it well. An obvious measure would be to generalize a 32 hours work-week, over 4 days. It would mean less unemployment and less overwork. Workload will reduce anyway. We might as well share this reduction, instead of giving it all to the unemployed.
Energy: when you don't need to own your car, you can use the best car for the job. A commuting car doesn't need to be able to carry 5 people around. It can be much smaller. Again, the transition period likely won't look good.
Harsher economic times: this is good old technological employment, where productivity rises faster than demand. My 2 cents: self-driving cars will significantly contribute to technological unemployment, and that's good, provided we manage it well. An obvious measure would be to generalize a 32 hours work-week, over 4 days. It would mean less unemployment and less overwork. Workload will reduce anyway. We might as well share this reduction, instead of giving it all to the unemployed.