California Code, Vehicle Code - VEH § 22504

(c)(1) A schoolbus stop shall not be designated where there is not a clear view of a proposed or existing schoolbus stop from a distance of 200 feet in each direction along a highway, or upon the main traveled portion of a highway where there is not a clear view of the stop from 500 feet in each direction along the highway and the speed limit is more than 25 miles per hour, unless approved by the Department of the California Highway Patrol upon the request of the school district superintendent or the head or principal of a private school. If the schoolbus stop is approved by the Department of the California Highway Patrol, the Department of Transportation, in respect to state highways, and local authorities, in respect to highways under their jurisdiction, shall place sufficient signs along the highway to give adequate notice to motorists that they are approaching such bus stops.

(2) A school bus stop shall not be designated on any divided or multiple-lane highway where pupils must cross the highway to board or after exiting the bus, unless traffic is controlled by a traffic officer or official traffic control signal. For purposes of this section, a multiple- lane highway is defined as any highway having two or more lanes of travel in each direction.