Thanks Scott.  I was just looking at the picture again & realized that he is driving on a dirt road, hence the touring coat buttoned up to the chin & the hat.  The dust clouds must have been horrendous to drive through.  I was looking at a photo on Shorpy one day last week of a wooden road grader, from about the same time period, that consisted of a large board, dragged by a horse.  The road was muddy &, even after all the hard labor, it still didn't look any too smooth.