Mo. Rev. Stat. § 49.275: County commission may provide transportation for county officers and employees (first class counties).

1. The county commissions in all counties of the first class not operating under a special charter for their own government may, in their discretion and in addition to any other allowance provided by law, provide such transportation for any county official, deputy or employee as is reasonably necessary to the efficient performance of his official duties.

2. Such transportation may be provided by furnishing county-owned automobiles or by paying a reasonable cash allowance for the use of privately owned automobiles, or by paying a fixed amount per mile for miles actually traveled in privately owned automobiles, or by furnishing gasoline and oil, or in such other manner, or combination of manners, as the county commission may direct.