Three times this morning I had to walk around somebody because the person in front of me just randomly walked diagonally across my path, as if I wasn't there. What's the story with that? I see this happening and I look ahead to see if there is a turn or staircase or something that the person is trying to get to. If so, I adjust my gait accordingly to let them pass. But when there's no reason for them to just be staggering to and fro across the sidewalk, I keep walking. None of them were even on the phone or otherwise engaged in something distracting. They just don't know how to walk.
Hey -- there's people on the sidewalk with you. They're trying to get to work too. Have enough awareness to know that you're about to walk into somebody.