It could save on battery power: If the user has been on the road, we can ping the GPS less often on the assumption they'll be mostly moving along one of a set o

It could save on battery power: If the user has been on the road, we can ping the GPS less often on the assumption they'll be mostly moving along one of a set of known paths. It could compensate for poor GPS availability, by allowing the track generator to make more informed guesses about where the user has been, if a GPS ping happens to get dropped.