CAL. HSC. CODE § 114315 : California Code - Section 114315

(a) A food facility shall be operated within 200 feet travel distance of an approved and readily available toilet and handwashing facility, or as otherwise approved by the enforcement agency, to ensure that restroom facilities are available to facility employees whenever the mobile food facility is stopped to conduct business for more than a one-hour period.

(b) This section does not limit the authority of a local governing body to adopt, by ordinance or resolution, additional requirements for the public safety, including reasonable time, place, and manner restrictions pursuant to its authority under subdivision (b) of Section 22455 of the Vehicle Code.