They’re badly designed (outskirts of Silicon Valley). So is the electricity and internet, so the transponders placed in shady spots would need something like a 30 day battery backup and network other than wired, cell, wisp or starlink.

Vision based systems would be more than adequate. Lidar or (god forbid) ultrasonic chirps would easily lead to superhuman safety and speeds.

I’m skeptical of transponder or network based systems. What happens during a natural disaster? Do the 10% of cars that lack drivers or steering wheels just stop and block the evacuation routes? That’d kill a lot of people in very graphic / high profile ways.