I think car free zones will be first. Paris anyone?
You could humanize vehicles. Look at golf carts or those small EV vehicles. Of course then restirct them to only emergency services, mass transit, deliveries, etc.
You could limit delivers at one time during the day say 5 am to 8am
You could build a subway system for Mass transit, Emergency vehicles, etc
You could build a canal system
There is the free state project they might help you out
http://www.freestateproject.org/