Eh, it's probably good to have regardless?

It's less about being careful around the car and more about how you might interact with it. For example, honking the horn or flashing your beams wouldn't have the same effect. On that note, it might be nice to have some way of telling a self driving car to temporarily use elevated sensors or something, the same way a horn tells a driver that something is wrong. As long as there's a way to prevent abuse of the system

I don't know much about these lights, but we COULD use some new standards in general with how many things have changed with cars in recent years. Brake lights on electric vehicles being another thing to consider.

That "gentle horn" everyone wants being another

As a Level 3 system, the driver is permitted to take their hands off the wheel, their feet off the pedals, and divert their attention away from the road. [...]

The turquoise markers will alert other drivers to the fact that your vehicle is driving itself, so hopefully they won't be alarmed if they see you doing other things while behind the wheel.

warning lights

Lol, this is like calling the turn signals warning lights. Letting others know something about your driving isn't a warning, it's just an indicator.

To play the devil's advocate: early cars needed a guy with a flag im front of them because people were used to horses and carriages and not automobiles. After a while that stopped being a thing.

But yeah, self driving cars are not really ready.

If we need signs saying student driver, the driver is not ready

There are warning signs to indicate people learning to drive in ex-Soviet countries (such yellow triangles to put behind the glass), even though they are driving with an instructor.

Now when I think about it, it's been some time since I've seen that sign.

Well, theirs probably isn't.