Mo. Rev. Stat. § 231.210

It shall be the duty of the road overseer to keep the roads in his district in as good repair as the funds at his command will permit. It shall also be his duty to keep all culverts and holes in the floors of bridges in his district repaired, and to make an inspection of the roads, bridges and culverts in his district as often as practicable and to see that they are kept in a safe condition.