Wash. Rev. Code § 81.112.110
If an authority acquires any existing components of a high capacity transportation system, it shall assume and observe all existing labor contracts relating to the transportation system and, to the extent necessary for operation of facilities, all of the employees of such acquired transportation system whose duties are necessary to operate efficiently the facilities acquired shall be appointed to comparable positions to those which they held at the time of such transfer, and no employee or retired or pensioned employee of such transportation systems shall be placed in any worse position with respect to pension seniority, wages, sick leave, vacation or other benefits that he or she enjoyed as an employee of the transportation system prior to such acquisition. At such times as may be required by such contracts, the authority shall engage in collective bargaining with the duly appointed representatives of any employee labor organization having existing contracts with the acquired transportation system and may enter into labor contracts with such employee labor organization. Facilities and equipment which are acquired after July 1, 1993, related to high capacity transportation services which are to be assumed by the authority as specifically identified in the adopted system plan shall be acquired by the authority in a manner consistent with RCW 81.112.070 through 81.112.100.
RCW 81.112.110