It's not an engineer's thing at all. The classifications are very specific differences in the overall system. From an engineer's point of view they are just creating a fully autonomous car. L4 -> L5 is more about how many scenarios is that fully autonomous car been tested through.
I think the key thing people need to realize from the SAE definition [1] of the levels is that they represent designs of the system rather than abilities of the system. I could slap a camera on my dashboard, tell the car to go when it sees green pixels in the top half of its field of view and stop when it sees red pixels. Then I could get out the car and turn it on, and for the 5 seconds it took for that car to kill a pedestrian and crash into a tree, that would be level 5 self driving.
So when people talk about a particular company "achieving" level 4 or level 5, I don't know what they mean. Maybe they mean achieving it "safely" which is murky, since any system can crash. Maybe they mean achieving it legally on public roads, in which case, it's a legal achievement (although depending on what regulatory hoops they had to go through, maybe they had to make technical achievements as well).
> L5 which means 100.000% covered, will not happen, but the PR people will continue to use the term.
Which is precisely why so many people are critical of the term "fully autonomous".
> 99.999% cases covered
What cases? The point is that edge cases are the issue with autonomous driving. I can fall asleep on a train or a plane because I know there is human conductor who can handle the edge cases. This doesn't exist with L4. Everything else that doesn't let me fall asleep (read a book, look at my phone, etc.) is only marginally better.
I've always thought of L5 as a car that can operate via its sensors + onboard computing alone, at least as well as a median human driver.
No communicating with a server to download maps, no perfect performance, just a car that knows the state's traffic laws driving a brand new road in any reasonable weather, and getting into less crashes than a human would.
https://en.wikipedia.org/wiki/Self-driving_car#Classificatio...