For the most part, we keep the nose wheel on the center line to
avoid any obstacles to the sides of the runway. On a taxiway,
and on the ramp, the center line is *supposed* to ensure that
the wings do not hit any obstacles, such as parked aircraft,
trees, etc. If you have the opportunity to listen to airport
weather reports (ATIS) shortly after a snowstorm, you may hear
a warning about "snow dirfts" or such 24 inch or higher. High wing
aircraft don't have as much to worry about since the wings are
5-8 feet above ground, depending on the aircraft.