Tejon Pass' major difficulty is the grade, and that's about it. PA may not have a highway that matches that grade, but many come close, and there are far more tight curves, typically far worse road conditions, and bad weather season is far more common than in N LA.
Highway trucking will be the first significant deployment of autonomous vehicles. One of the big challenges is Mountain West interstates.
I do agree that the NE US is a proper testbed for bad weather city driving, since no West Coast cities have really that bad winter weather, I'm just objecting to the claim that somehow Pittsburgh captures all the challenging road conditions that autonomous vehicles will encounter.