Do you not see my point? How about traffic lights? Or street lights. It’s the same thing. You make it sound like things can’t improve from status quo. Let me guess you are a Java dev.
I don't think we'd do away with street lights even if the cars could see in the dark. Traffic lights we'll need for as long as human driving isn't illegal, which is at least 50 years.
Safety is pretty much irrelevant unless its uniform with no large dips in intended design. Have existing roads. Have human driver cars, and autonomous cars which use all the same signals the humans use. These things don't advance as fast as some areas, so putting the cart before the horse has no benefit here. Even if we want to progress as fast as possible!
And there's streets outside cities too. The ugliness of fragmentation with your way is too painful to think of. Like soviet roads where suddenly its undrivable.
If we want to develop general purpose machines, then we can rely on placing external sensors in the environment