RCW 47.26.170

Each county having within its boundaries an urban area and cities and towns shall prepare and submit to the transportation improvement board arterial inventory data required to determine the long-range arterial construction needs. The counties, cities, and towns shall revise the arterial inventory data every four years to show the current arterial construction needs through the advanced planning period, and as revised shall submit them to the transportation improvement board during the first week of January every four years beginning in 1996. The inventory data shall be prepared pursuant to guidelines established by the transportation improvement board. As information is updated, it shall be made available to the commission.