Combine driverless cars with electric motors. Add a few driver-free high speed tunnels which connect to the existing road network (I assume tunnelling will eventually be cheaper than building new roads). Then we'll have a growing, backwards-compatible high speed freight distribution system which delivers to the doorstep. And as cars get quieter and pollution free (locally) our cities will suddenly become civilised places to walk around in, breathing freely. Maybe we'll hang out like philosophers in the market squares of Athens or Florence :-)
