You said the bike rider came from the opposite direction? Were there signs on the other end of the bridge that he/she might have seen?

Yes, riding on a bike where there is heavy pedestrian traffic is rude. Especially on sidewalks. ON THE OTHER HAND, I have seen people walking - often two or three abreast - ALONG A MARKED BIKE TRAIL. Isn't that equally rude? Wouldn't pedestrians walking on a marked bicycle route constitute an equal violation? You see that all the time on larger college campuses...