Mo. Rev. Stat. § 226.798: Factors considered in designating a road or highway a scenic byway — rating system to be established.

1. The highways and transportation commission shall consider, at a minimum, the following factors in designating a road or highway as a scenic byway:

(1) Highway design which preserves and protects the natural beauty or scenery of the area;

(2) Significant scenic, natural, historical, cultural or recreational resources in the area;

(3) Adequate land area to accommodate safe enjoyment of scenic attractions;

(4) Compatibility of the scenic byway with recreational, aesthetic and environmental management needs of the area; and

(5) Presence of existing protected areas near, or adjacent to, the scenic byway, such as national forests or federal or state park land.

2. The commission shall adopt a rating system to ensure that only roads and highways that display outstanding characteristics pursuant to the provision of subsection 1 of this section are designated as scenic byways as provided by the provisions of section 226.797.