Mo. Rev. Stat. § 233.415: State roads — cost of improving and upkeep — how paid.

Whenever any road or highway in said special road district shall be designated and approved by the state transportation department as a state road, then the state shall pay at least one-half of the expense of constructing or improving said state road, and the procedure for obtaining such state aid shall be the same as is now or may hereafter be provided by law for the obtaining of state aid in other road districts of the state.