Mo. Rev. Stat. § 137.595: Taxes — how collected — how kept.

All taxes levied under the provisions of section 137.585 shall be collected in the same manner and at the same time as taxes for county purposes are now collected, and all moneys arising therefrom shall be appropriated, set apart and kept as a special road and bridge fund, and shall be used for road and bridge purposes, and for no other purpose whatever.