It shall be the duty of the engineer trainee, appointed under provisions of this article, subject to approval and direction of the county commission or like governing body, to assist the county engineer or chief engineer of the division of public roads of said county in all duties of said engineer as prescribed by law or as directed by the county commission and to perform such other duties as necessary and incident to the operation of the county highway system.
Ala. Code § 11-6-22 (1975)