Vehicle Code section 21657

The authorities in charge of any highway may designate any highway, roadway, part of a roadway, or specific lanes upon which vehicular traffic shall proceed in one direction at all or such times as shall be indicated by official traffic control devices. When a roadway has been so designated, a vehicle shall be driven only in the direction designated at all or such times as shall be indicated by traffic control devices.

Source: Section 21657, https://leginfo.­legislature.­ca.­gov/faces/codes_displaySection.­xhtml?lawCode=VEH§ionNum=21657.­ (updated Jan. 1, 1969; accessed Jun. 25, 2025).

Green check means up to date. Up to date

Verified:
Jun. 25, 2025

§ 21657's source at ca​.gov