geometry), don't generate crosswalks or stop signs. In reality, these
usually represent the middle of a complicatd intersection. Ideally these
cases would be merged into a single intersection, but before that's
feasible, at least improve some of the inferred things nearby. #457
Originally it was split out to organize a separate volunteer mapping
effort, but that never took off, and it's unlikely to happen. When we
have to occasionally update the prebaked signal data for some
intersections, it's unnecessary friction to update the other repo.
