St. Louis County, MO Mobility & Curb Rules: Bike Lane Rules (2026)

Section 1210.055 of the county's Traffic Code sets the baseline: when a cyclist moves slower than traffic, the rider must generally take the right-most through lane, but the ordinance carves out lawful exceptions, including, in its own words, '(iv) Riding on parts of roadways set aside for the exclusive use of bicycles, including, but not limited to, contra-flow bicycle lanes, left-handed cycle tracks or bicycle lanes on one-way streets, and two-way cycle tracks or bicycle lanes.' Wherever St. Louis County has striped a bike lane or cycle track, a cyclist is entitled to use it and is not confined to the right edge of a general travel lane.

The same section also protects a cyclist who leaves a lane to avoid a hazard, states a compliant cyclist 'is not impeding traffic' under subsection 3, and allows riding two abreast on paths, shoulders, or roadway sections set aside exclusively for bicycles under subsection 4(b). On the driver side, Section 1212.175 requires a motorist overtaking a cyclist to move into an available adjacent lane or, on a single-lane road, to 'pass to the left of the person operating a bicycle at a safe distance, which must not be less than three (3) feet between any portion of the vehicle and the bicycle.' Because Chapter 1212 carries no dedicated penalty section, a driver violation of the three-foot rule is prosecuted under the county's general Traffic Code misdemeanor penalty at Section 1215.010: up to a $1,000 fine, up to a year in jail, or both. A cyclist violation of Section 1210.055 instead falls under Chapter 1210's flat penalty, Section 1210.110, capped at $10.