Ala. Code § 32-5A-384: Compliance with National and Departmental Guidelines.

The department or authority, or its contractor, shall place traffic control devices in conformity with a nationally recognized traffic engineering handbook, including, but not limited to, the Manual of Uniform Traffic Control Devices and the traffic control plans of the department. There is a presumption that the department’s actions are in compliance with this section unless the contrary is shown by a preponderance of the evidence.