text: https://www.openstreetmap.org/relation/9712073
  
  The route is labeled as line "SS" in osm, but the actual signs in the real world just say "S", including the one here.  I don't believe the current buses show route letters at all, but the older ones always used "N" and "S" for the North and South night safety shuttles.  
  
  Confusingly, the website is now calling them routes "NSN" and "NSS".