[CoffeeOnWrite]

What’s your angle here?

In practice humans frequently neglect to signal in instances where it is legally required (I don’t know if it is strictly legally required in California when parallel parking, but it’s certainly good common sense). Human drivers know that people don’t signal and account for that.

In this particular scenario the reverse lights would be a crystal clear indication of the driver’s intent, even if they failed to signal.

I don’t want to assume the intent of your comment, I don’t know what you’re getting at..

[jeffbee]

Just wondering because it's not always apparent that a car is slowing to park parallel, especially if they don't signal. The only way I know to make it really clear is to stop alongside the open spot, signal, move ahead slowly and put it in reverse, but half the time humans still don't get the message.

[CoffeeOnWrite]

So what do you do?

I have never run into this where the human driver didn’t get the hint when I remained in front of them with my reverse lights on. They have somewhere to be so sooner or later they go around me (backing up if necessary). From my understanding, the driverless car in the OP just sat there forever.