Section 28100 Of Article 15. Pilot Cars From California Vehicle Code >> Division 12. >> Chapter 5. >> Article 15.

. A pilot car shall display at least one red warning flag on each side of the vehicle. The flags shall be a minimum of 16 inches square, and shall be mounted so as to be visible from both the front and rear of the vehicle. The flags shall be removed or covered when the vehicle is not operating as a pilot car.