Buchanan Street Mall seems to have gotten messed up. Lots of self-intersecting highway=pedestrian way(s). It's hard to tell what happened exactly but it looks like a bunch of stuff was deleted and sort of redawn (maybe?) in http://www.openstreetmap.org/changeset/54453945 , and maybe some other changesets? (There were a ton of edits by the same user in rapid succession around here)