 The Washington state highway system was changed to its current "sign route system" beginning in January 1963 with a state highway renumbering.Under the new system, Interstate highways, U.S. routes, and state routes replaced the primary and secondary highways and were codified under the Revised Code of Washington in 1970.US 2 was re-routed around various cities over the next several decades onto limited-access highways to reduce congestion, beginning with the construction of the current westbound Hewitt Avenue Trestle east of Everett in the 1960s, moving traffic off an existing wooden trestle that would be replaced with a new eastbound trestle in 2002.