I counted about 40 of these Waymo driverless autonomous self driving vehicles just driving between my house and a restaurant the next city over. Weird seeing cars driving around with an empty driver's seat, they're everywhere. Wondered how many had passengers and how many were just on their way to pick
up passengers or just driving around to exercise the programming or something.
So it occurred to me, taxis in the past (although I guess they're not totally replaced yet) had a light on the top showing if it was available or not but that's not possible with these self driving cars since their main guidance camera is up there.
So the idea is to just turn the light inside on which would make it very obvious that it's empty, not just that you'd see there was nobody in the back seat, but it would clearly see it from a good distance like the old taxi lights because people don't drive with their cabin light on, it's unsafe and nobody does it. You see a robotaxi with the cabin light on, it's available.
Of course if it was going back to get charged or something it would be off as well. They'd be barely illuminated so as not to cause a visual hazard. Maybe just the back seat glowing a bit. Just enough to show it's empty.