Wash. Rev. Code § 47.12.190
The department, in addition to its other powers and duties as provided by law, is authorized to purchase or condemn any real property or property rights therein which it deems will be necessary for the improvements of routes on the state highway system by the method provided in RCW 47.12.180 through 47.12.240. Condemnation actions brought hereunder shall be brought in the name of the state as provided for acquiring property for the public uses of the state, and in such actions selection of the property and property rights by the secretary of transportation is conclusive that they are necessary for the purposes sought, in the absence of bad faith, or arbitrary, capricious, or fraudulent action.
RCW 47.12.190
Severability-1961 c 281: See note following RCW 47.12.180.