[gruez]

>Obviously they're not treating the sidewalk as part of the road

From wikipedia:

"The primary features of roads include lanes, sidewalks (pavement), roadways (carriageways), medians, shoulders, verges, bike paths (cycle paths), and shared-use paths. "

Emphasis mine

>and why should they? In sensible countries walking in the general traffic lanes of a regular street is be fine.

I don't know what "sensible countries" you're talking about. Sidewalks are hardly some sort of concept exclusive to car-centeric America. Even bike/pedestrian friendly European countries have separate lanes for pedestrians, with some very limited exceptions such as during festivals/events.

[lmm]

From the Cambridge dictionary: "a long, hard surface built for vehicles to travel along". So not a sidewalk.