That's a completely different matter, though, in that it's not permissible to ride a bike on a sidewalk pretty much anywhere (here, we must use the bike path al

That's a completely different matter, though, in that it's not permissible to ride a bike on a sidewalk pretty much anywhere (here, we must use the bike path although I'd prefer the street which is the case elsewhere). It's reasonable to be upset at people breaking codified behaviour (law, even) – similar to a pedestrian walking down the road instead of the sidewalk. The intra-sidewalk issue of various pedestrians wandering around aimlessly, stopping randomly, walking inexplicably slowly &c. is the studied topic. I must admit, I get quite frustrated with the above though not to the point of being angry let alone enraged. I've always imagined that city people are better at passively taking others into account when moving but that might make an interesting study as well.