How long would changing infrastructure and cars to better support self-driving take? Many cars will continue to be on the road for many years. What are the costs of adapting all of them?
IF that really happens, it would take at least a decade and Waymo's lead from network effects, more mature tech, more self-driving data, etc would be enormous by then.
A few weeks or so, for the first stretches of road. Self-driving cars can be useful even if limited to limited stretches of road (for example, many people would pay for the ability to read a book or play a video game in the 30 minutes they spend on the highway to work, even if that initially were the only stretch of road where their car were autonomous), and such roads could be made off limits to older cars.
And cost? Not that large, compared to the cost of building roads.
IF that really happens, it would take at least a decade and Waymo's lead from network effects, more mature tech, more self-driving data, etc would be enormous by then.