(1) Subject to RCW 46.61.400(1), and except in those instances where a lower maximum lawful speed is provided by this chapter or otherwise, it shall be unlawful for the operator of any vehicle to operate the same at a speed in excess of twenty miles per hour when operating any vehicle upon a highway either inside or outside an incorporated city or town when passing any marked school or playground crosswalk when such marked crosswalk is fully posted with standard school speed limit signs or standard playground speed limit signs. The speed zone at the crosswalk shall extend three hundred feet in either direction from the marked crosswalk.
(2) A county or incorporated city or town may create a school or playground speed zone on a highway bordering a marked school or playground, in which zone it is unlawful for a person to operate a vehicle at a speed in excess of twenty miles per hour. The school or playground speed zone may extend three hundred feet from the border of the school or playground property; however, the speed zone may only include area consistent with active school or playground use.
(3) A person found to have committed any infraction relating to speed restrictions within a school or playground speed zone shall be assessed a monetary penalty equal to twice the penalty assessed under RCW 46.63.110. This penalty may not be waived, reduced, or suspended.