Have been wondering the same thing myself. I live at Ariel Dunes and thought he was just walking to the store or work, till i started seeing him no mater the time of day I was out. My next theory was he was collecting cans for recycling, but the small plastic bag he always has never seems to change in size.
Note: he does walk in the bike(?) lane that separates the turn lane from the hwy in font of US Gold and the gas station on 98 and Holiday..also takes the bike lane on the turnoff from 98 to Seascape. I always look for him there now when I am turning. He is very had to see at twilight. Make sure to look twice when turning off of 98.