Yes, that reminds me of the stretch on the 101 near Palo Alto that has two sets of lane markings (one old and slightly faded out but still very visible, and one newly repainted). Of course, drivers should only follow the newly painted set of lane markings.

Even as a human, I get confused while driving on this stretch. The old lane markings aren't quite faded out enough to easily tell them apart. As I'm driving, I see every other car slowing down and "dead reckoning," too.

How will the run-of-the-mill self-driving car's lane following handle this corner case? If it's a Canny edge detector (like most self-driving cars), it's definitely going to fail and find false positives.