Some special considerations apply to the problems of agency in cases involving motor carriers. The questions here presented are viewed in the light of the operating practices which obtain in the industry. Relatively few tractor-trailer or truck trailer outfits are owned by the certified carrier. The equipment is usually owned by an individual, who may drive it himself as an owner-driver; or may hire his own driver and lease the equipment and driver together to the carrier. The lease may be for a single movement only, covering one trip from a stated origin to a stated terminal; or may be for a longer term. The long term leases are usually for one year, subject to cancellation on written notice by either party. There seems to be no standard form of either single trip or long term lease.
Craig Spangenberg, Agency Problems in Motor Carrier Cases, 6 Clev.-Marshall L. Rev. 130 (1957)