RCW 46.61.730
RCW 46.61.730: Wheelchair conveyances.
(1) No person may operate a wheelchair conveyance on any public roadway with a posted speed limit in excess of thirty-five miles per hour. (2) No person other than a wheelchair-bound person may operate a wheelchair conveyance on a public roadway. (3) Every wheelchair-bound person operating a wheelchair conveyance upon a roadway is granted all the rights and is subject to all the duties applicable to the driver of a vehicle by this chapter, except those provisions that by their nature can have no application. (4) A violation of this section is a traffic infraction.