Why would pedestrians choose to walk on a busy road rather than use the sidewalk? I encountered this situation twice yesterday on my commute, where a pedestrian walking on a busy road forced me to move further out into the lane -- even though there was a nice sidewalk alongside the road. I understand that some runners prefer asphalt pavement to concrete sidewalks because the asphalt is supposedly "softer" and flatter. But I am totally baffled as to why a pedestrian would do this.
I am tempted to yell "Get on the sidewalk!" to them, but would rather not since so many drivers yell that at cyclists all the time, even though we are legally supposed to ride on the road.