The second disregard, that well... there are airplanes.
The first, that driverless busses that creep at 30km/h and do emergency brake every every 10 minutes thanks to overattentive collision avoidance system also been around for decades.
But then, you effectively get a copy of a rail system, only without rails. Saudi experimental city once played with the concept
And the same parallel for driverless car, except for even when well executed it is kinda of arguable usefulness/value.
Are regular cars useful? A self-driving car is just as useful for someone who can't drive: minors, many seniors, many people with disabilities - or people who just don't have a driving licenses, like me.
I expect them facing same issues like trams and trolleybuses - terribly bad experience in traffic.
You only see risky people aggressively trying to overtake and scratching their paint, while leaving the driver no opportunity to move an inch.