Wash. Rev. Code § 46.90.005
The purpose of this chapter is to encourage highway safety and uniform traffic laws by authorizing the department of licensing to adopt a comprehensive compilation of sound, uniform traffic laws to serve as a guide which local authorities may adopt by reference or any part thereof, including all future amendments or additions thereto. Any local authority which adopts that body of rules by reference may at any time exclude any section or sections of those rules that it does not desire to include in its local traffic ordinance. The rules are not intended to deny any local authority its legislative power, but rather to enhance safe and efficient movement of traffic throughout the state by having current, uniform traffic laws available.
RCW 46.90.005
Effective dates-1993 c 400: "(1) Sections 3 through 5 of this act are necessary for the immediate preservation of the public peace, health, or safety, or support of the state government and its existing public institutions, and shall take effect immediately [May 15, 1993].
(2) Sections 1 and 2 of this act is necessary for the immediate preservation of the public peace, health, or safety, or support of the state government and its existing public institutions, and shall take effect July 1, 1993.
(3) Section 6 of this act takes effect July 1, 1994." [ 1993 c 400 s 7.]