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.
Why do you assume most self-driving cars use Canny edge detection? And even if they did, you can simply have the algorithm choose the higher threshold (with some other sanity checks, suck as are the lines the expected distance apart) and ignore the lower threshold.
The algorithms for lane following are quite a bit more sophisticated than that though. Here's a paper from 2008, and there are other approaches as well.
Hough lines/RANSAC are definitely on the same level of ad-hoc sophistication as Canny edges (in fact, Canny edges are often done as a preprocessing step for the voting scheme used by the candidate Hough lines).
Take a look at Figure 12 for an exemplary look at its failure cases -- cases that are much less forgiving than the aforementioned Palo Alto stretch 101 lane markings.
I'd have thought road-marking interpretation would nowadays be based on something more elaborate, such as HOG, without the need for an initial edge-detection pass.
(But in this case, I'll add that HOG doesn't solve the problem of overlapping old/new road 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.