Definitely not better road markings. I'm a Pittsburgh native, having spent most of my life there, and if anything the immaculate roads here in NorCal are a part of the ongoing skewed optimism regarding self-driving vehicles.
In Pittsburgh, you have potholes, ubiquitous construction (especially on PA-28), bridges (and I'm not talking Bay Bridge esque suspension bridges here), windy single lane dirt roads without markings, to say nothing of winter (snow usually obstructs what little markings there are 6-8 months out of the year), and a completely different driving style than in NorCal. Most people in Pittsburgh drive trucks or four-wheel drive Subarus (indeed, Pittsburgh has been a good niche market for Subaru -- they focus a lot of their advertising there). In Pittsburgh, roads only have two lanes max in each direction (and that's the highways). Even downtown has its fair share of dirt roads (near Allegheny River) and brick roads (roads that are made of bricks). I was shell shocked when I first moved to California and drove on the 101 with its 4 perfectly paved lanes filled with drivers exceeding 50 MPH.
Precipitation is a nightmare for self-driving cars' LADAR sensors, rendering them completely unusable. Drought-afflicted SV has zero precipitation, and Pittsburgh has almost as much as Seattle. Driving in snow is such a drastically different task/skill than driving in perfect weather that most people in California don't even know how to drive in Tahoe on their skiing trips (and the "snow" there is maintained by humans!).
If anything, us Pittsburgh-based autonomous vehicle researchers are the ones more grounded in reality. Elon hasn't even seen "the Turnpike" -- it is sad to say that the rather unfortunate fatal Tesla autopilot accident happened here in Pittsburgh.
As aside, Sebastian Thrun was in snow-laden Boston, and he and his lab also have a more realistic time estimate for driverless vehicles hitting the road than TechCrunch.
Anytime anyone in California complains about the roads (and believe it or not, people do complain about them here a lot), I just laugh.