I could see that another car in front of the 18 wheeler was slowing down too fast to make an off-ramp, forcing the truck to quickly swerve into my lane
Still a problem whilst non-autonomous (or, at least, human-driven but non-communicating) cars are still on the road, but I think this sort of thing will be solved? (or at least "improved"?) by vehicle to vehicle (V2V) comms. There are, I think, a number of opportunities for V2V to be used in this situation:
Car in front "I'm braking very heavily"
Truck "I'm bearing down on car in front and cannot stop in time so will need to swerve"
Another classic example is an aluminum ladder laying in the middle of the road.
I get alerts for that type of thing on Waze. When I first started getting "
Car stopped on hard shoulder" (i.e. where there is a physical lane for that purpose, as distinct from "
Car stopped on road") I thought it was chaff: that's what that lane is for, and the chance that I might need to take evasive action on such roads, in such a situation, is astonishingly small ... but now I appreciate those warnings as it gives me that tiny bit more Data in case it is ever needed. I never bother to enter car-stopped-on-shoulder into Waze (but I do if the car is stopped on the road, or a policeman is hiding in the hedge
), so I assume that the number of people prepared to log that, compared to the number of Waze drivers who pass it, must be small - and the number of Waze drivers compared to the total vehicles on the road must be tiny. But I still get those warnings - its rare to see a vehicle stopped and NOT get a warning.
So that is just for Data Points manually entered by another (Waze-using) driver on the road ... cars themselves detecting such obstructions and announcing them to other cars will be better, and more commonplace.
That doesn't stop the first vehicle ploughing headlong into the ladder though ... unless some other Tech can detect it, and also "announce" it - so we might still have an initial accident under L5? but not a pile-up.
Plus:
If the car-in-front was L5 it would not be having to brake so heavily
If the Truck was L5 it would be following at a safe-stopping distance - or drafting the vehicle in front if it was able to V2V with that vehicle to collaborate on any slowing-down requirements.