The Department of Transportation shall have the power, and its duty shall be to divide the State into suitable districts or divisions or both, and place in charge of each such district or division or both such person as the Secretary of Transportation may in his discretion deem advisable to serve at the pleasure of the secretary. Each such employe shall perform such duties in connection with his district or division or both as the Secretary of Transportation shall prescribe.
71 P.S. § 514