Mo. Rev. Stat. § 228.160
Any person wishing to cultivate or enclose land through which any road may run may petition the county commission, first giving notice, as in the case of new roads, for permission to turn such road on his own land or on the land of any other person consenting thereto, at his own expense. The commission shall thereupon cause the county highway engineer to view the same and report the practicability of the proposed change and distances and situation of the ground, and proposed changes, at the first term of the commission thereafter; and if upon the report the commission be satisfied that the public will not be in any manner injured thereby, or said road lengthened or the grade thereof increased, or the road thrown on rougher land, it shall order such a change, and upon satisfactory proof of such road being opened in such manner as to be equally convenient to travelers, the commission shall make an order vacating so much of the former road as lies between the different points of intersections, and cause the report thereof to be recorded.
§ 228.160, RSMo