When we started traveling, we never guessed that one of our surprising sources of stress would be sidewalk etiquette. It turns out that moving to “your side” of the sidewalk half a block ahead of an oncoming stranger is a fairly American and Northern European phenomenon. We had way too many near-misses and thoughts of “why the hell does it seem like everyone is walking straight at us!” before we started to get the hang of the regional nuances.
The simplest way to sum it up is that some cultures seem to have less of a personal space bubble, and therefore are totally comfortable getting within inches of an oncoming stranger before pivoting slightly and missing by millimeters (if that). It’s not too hard once you get the hang of it, but it takes suppressing the instinct to move aside early – that tends to be misinterpreted as a change in direction.
Note that this is on top of, and distinct from, the general ambivalence some more inconsiderate folks exhibit toward their fellow pedestrians. But simple rudeness is by no means a regional trait.