The Stallcups lived in a rural section of the state. In front of their house ran a relatively unused, unimproved public county road. Wales Trucking Co. transported concrete pipe from the plant where it was made to a lake where the pipe was used to construct a water line to bring water to a nearby city. In the course of four months, Wales made 825 trips over the road, carrying from 58,000 to 72,000 pounds of pipe per trip and making the same number of empty return trips. Because the heavy use of the road by Wales cut up the dirt and made it like ashes, the Stallcups sued Wales for damages caused by the deposit of dust on their house and for the physical annoyance and discomfort it caused. Wales defended its position on the ground that it had not been negligent and that its use of the road was not unlawful. Decide. [Wales Trucking Co. v. Stallcup, 465 S.E.2d 44 (Tex. App.)]