Columbia Authority to sign one-way streets and alleys ordinance (§ 14-202)
Chapter 14: Motor Vehicles and Traffic · Article IV. Operation
In short: A one-way street or alley rule in Columbia isn't enforceable unless signs are posted. The city traffic engineer must put up and maintain those signs, including at every intersection where traffic going the opposite way is prohibited.
Our plain-English summary, not the official text or legal advice. The ordinance below is what counts.
Whenever any ordinance of the city designates any one-way street or alley, the city traffic engineer shall place and maintain signs giving notice thereof, and no such regulation shall be effective unless such signs are in place. Signs indicating the direction of lawful traffic movement shall be placed at every intersection where movement of
traffic in the opposite direction is prohibited.
Official source: City of Columbia official Code of Ordinances (online): look up Sec. 14-202
Text from Supplement 139 (September 3, 2026).
Last checked November 1, 2026. The city's official copy controls; this page is a reading copy, not legal advice.