RCW 46.61.660 (pasted below) prohibits a driver from allowing anyone to ride in the bed of a pickup. This and other rules of the road can be viewed in Chapter 46.61 of the Revised Code of Washington, also available at the state legislature's website at http://apps.leg.wa.gov/rcw/default.aspx?cite=46.61. In addition to the rule pasted below, letting kids ride in the back of a pickup violates RCW 46.61.688, which prohibits transporting children under 16 who are not properly seatbelted and/or in...