In the first sentence of the second paragraph, the author includes the parenthetical statement about the "sensible writer" primarily to.

With any turning vehicle, the rear wheels follow a shorter path than the front wheels. the longer the vehicle is, the greater the difference will be. truck drivers initially swing out before making a turn. what isn't shown in this illustration is as car straightens out, the front wheels must travel a greater distance and the tail end drags on the shortest path.