Oh, I see, sorry. I think the "as well as they do now" is a constraint which means the answer will be null because of continuous improvement.
But I believe the video with the blind guy does have a long form version somewhere, so if you consider that (different vehicle, much older technology) to be "as well as they do now" in the sense you meant then that's still roughly in the six year mark.
xracy talked about autonomous vehicles which will include at least trains. London's Victoria Line underground service build in the 1960s was always ATO, which is closer to L4 in this scheme than L3, under normal operation the original Victoria Line trains basically require the driver to push a button, closing the doors and then once the train concludes all of its doors are safely closed it will leave, drive to the next station, stop and open the doors, then we just rinse and repeat.
Now, trains don't actually use the car terminology, in trains we'd call this GoA2, Grade of Automation 2, with the next steps being GoA3 in which there's a human who knows how to operate the train manually in principle, and they are on the train, but they aren't up front "driving it" unless something went wrong; and then GoA4 in which the train doesn't have anything resembling a human driver it just has passengers, in an emergency some central authority will set out to rescue the passengers from their disabled train. There are a handful of GoA4 train systems, but they're probably only 5-10 years old.
The video you posted is two weeks old.