As a pedestrian in SF, I feel a lot more threatened by cyclists than by cars. The car-pedestrian right of way rules are clearly established, but the pedestrian-cyclist rules, if they exist, seem to be ignored by cyclists. I have numerous times had cyclists bike 2 feet in front of me instead of stopping at a pedestrian crossing. I am not sure cyclists in SF grok the idea of a stop sign either. Same thing with traffic lights, which a lot of cyclists treat as mere suggestions.