Big changes that will come about from robocars will come from how they free car designers from the constraints of human-driven cars which are the owner’s sole, or almost-sole vehicle.
If one can hire a cheap specialized “robotaxi” (or whistlecar) on demand when one has a special automotive need, car users can elect to purchase a vehicle only for their most common needs, rather than trying to meet almost all of them — or to not purchase at all.
Most trips are short, have only one passenger and do not require significant cargo room. Almost nobody purchases a vehicle good only for that purpose, because they want to cover the occasional needs for long trips, taking extra people, carrying cargo, towing or going off-road.
So if on demand robotic cars are always roaming nearby then they could be instantly called when you need to carry more people or more cargo.
Design Possibilities of Robotic Cars
Long range is less important. (Call a long range car when needed)
Robotic electric cars can go and charge themselves.
All robotic car refuel/recharge can be done after dropping off passengers
Single passenger vehicles will be more common and can enable narrow roads
More reverse and face to face seating
Windshields would be optional
Acceleration and speed are not big requirements
Cars could safely become much lighter
Owners renting robotic cars
No humans involved in parking