If the iCar is truly revolutionary (for instance, it can guarantee you will NEVER get into a fatal car accident) then I'd say the "full road" is a small sacrifice.
People who want the full road can still buy traditional cars, right?
The iCar might rely on special features in the full roads to provide some level of automated steering.
I've considered some passive "beacons", shaped as nails, to be placed in roads, that can outline the lanes, complete with information about direction, speed-limits, exits etc. A smart car should be able to use those, along with a (ra|li)dar, to provide automated steering on equipped roads.
People who want the full road can still buy traditional cars, right?
Vote with your dollar.