Ala. Code § 23-1-176

All contracts of the corporation for the construction, reconstruction and relocation of roads and bridges, and work incidental or related thereto and the acquisition of property necessary therefor, shall be in writing, shall be subject to the rules and regulations and shall be let under the supervision of the State Department of Transportation and shall be subject to approval by the Governor and by the State Department of Transportation. All work provided for in any such contract shall be supervised by the State Department of Transportation. All persons engaged in the supervision or performance of any such work of construction, reconstruction or relocation that may be done by the corporation without the award of a contract therefor shall be employees of the State Department of Transportation. Any property acquired by the corporation by purchase, condemnation or otherwise shall be forthwith conveyed to the State of Alabama. All roads and bridges constructed by the corporation shall constitute part of the public highway system in the state.