Its a good swag at effects. I doubt you'd get the cities to 'give back' the space on the streets but it would change how new cities are built. Given how reasonably efficient self driving cars are now, I'm kind of surprised there isn't a move on to make a self driving 'truckway' up and down the state at least. Its got to be easier than hiring drivers and the equipment re-use is huge. Adding technology along the roadbed for extra safety, getting trucks out of the current population on highways, etc etc.