Ala. Code § 23-2-161
The department is hereby authorized, subject to the approval of the Governor, to expend funds from any available source as may be necessary for the study of any proposed toll road, bridge, or tunnel project authorized under this article and to use its engineering and other forces, including consulting engineers and traffic engineers, for the purpose of effecting the study. All expenses incurred by the department prior to the issuance of revenue bonds under the provisions of this article shall be paid by the department and charged to the appropriate project or projects and the department shall keep proper records and accounts showing each amount so charged.
Upon the sale of toll road, bridge, or tunnel revenue bonds for a toll road, bridge, or tunnel project, the funds so expended by the department in connection with a project shall be reimbursed by the authority to the department from the proceeds of such bonds and thereafter all expenses incurred in carrying out the provisions of this article shall be payable solely from funds provided under the authority of this article.
Nothing in this article shall be construed so as to authorize the authority to incur indebtedness or liability on behalf of or payable by the state or by any of its political subdivisions.
Ala. Code § 23-2-161 (1975)