Costa Mesa, CA Mobility & Curb Rules: Bike Lane Rules (2026)

Section 4-23 defines a "bicycle lane" as the portion of a public street distinctly marked on the pavement, with identifying signs, separating the space bicycles use from the space motor vehicles use, and recognizes Class I through Class IV bikeways under the CalTrans Highway Design Manual. Section 4-26(a) bars driving a motor vehicle in a bicycle lane established under Vehicle Code Section 21207, with three narrow exceptions: parking where permitted, entering or leaving the roadway, and preparing for a turn within 200 feet of an intersection; motorized bicycles and electric bicycles defined in Section 4-22(b) are separately allowed in the lane at a reasonable, non-endangering speed.

Section 4-26(b) requires any cyclist moving slower than surrounding traffic to ride within the bicycle lane, leaving it only to pass another bicycle, vehicle or pedestrian, to prepare for a left turn, to avoid debris or hazardous conditions, or when approaching an authorized right turn; Section 4-26(c) requires a cyclist to signal before leaving the lane if it could affect another vehicle. On streets without a bike lane, Section 4-26(d) requires slower cyclists to ride as close as practicable to the right-hand curb, with similar exceptions for passing, turning, hazards and one-way multi-lane roads.

Section 4-26(e) through (i) add general safety duties: no unreasonable speed endangering pedestrians or others, yielding to pedestrians on sidewalks (including Class I Multipurpose Trails, treated as sidewalks), yielding when entering a roadway from private property or a sidewalk, and riding only on a proper attached seat. Section 4-27 requires the Transportation Services Manager to design and post bicycle lane and regulatory signage readable by school-age children, and the chapter was substantially updated by Ordinance No. 2024-08, adopted July 16, 2024.