it's worse than that, of course. You'll find, like a certain Greek philosopher fond of asking annoying questions, that the first 90% of the last 10% will be OK, and that last 10% will be the other 90% of the ... etc. etc. etc.
In 2019 the idea of a vehicle around you simply stopping because its driver doesn't know how to handle a situation is extremely rare.
I suspect that by 2039 it will be far more commonplace, shrugged off as just a fact of life that electronic drivers fail on a regular basis and need to pull over and wait either for intervention or conditions to change.
It happened about as often as it happens to me with a cellphone when neither party is moving between towers and has decent coverage.
We expect cell drops because of a technology constraint, even in big cities. Likewise, I think the parent poster is right that we'll expect it more once it starts happening more.
That's a huge improvement over the last 10% being difficult!