RCW 36.82.110: Voluntary contributions for improvements to county roads—Standards.

Upon voluntary contribution and payment by any person for the actual cost thereof, such person or legislative authority upon the approval of maps, plans, specifications and guaranty bonds as may be required, may place crushed rock gravel or other road building material or make improvements upon any county road. Such work shall be done in accordance with adopted county standards under the supervision of and direction of the county engineer.