It shall be the duty of the county commission to fix, from time to time in accordance with prevailing economic conditions, the various scales of wages or salaries to be paid for labor necessary in the maintenance and construction of roads, highways, bridges, and ferries; and the wage or salary scale shall not be exceeded by the engineer in the employment of labor and assistants.

(Act 88–894, 1st Sp. Sess., p. 447, § 5.)