Vehicle Code section 25301
(a)
During daylight warning devices shall consist of either:(b)
During darkness the warning devices shall consist of either:(c)
The provisions of subdivision (a) or (b) do not prevent the display of both types of the warning devices during daylight or darkness.(d)
During either daylight or darkness, no warning device is necessary if the vehicle is equipped with the flashing warning lights visible to approaching traffic from each direction as provided in subdivision (b).
Source:
Section 25301, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=25301.
(accessed Apr. 24, 2025).