Wash. Rev. Code § 81.80.060
Every person who engages for compensation to perform a combination of services, a substantial portion of which includes transportation of property of others upon the public highways, is subject to the jurisdiction of the commission as to such transportation and shall not engage in such transportation without first having obtained a common carrier or contract carrier permit to do so. A combination of services includes, but is not limited to, the delivery of household appliances for others where the delivering carrier also unpacks or uncrates the appliances and makes the initial installation. Any person engaged in extracting or processing, or both, and, in connection therewith, hauling materials exclusively for the maintenance, construction, or improvement of a public highway is not engaged in performing a combination of services.
RCW 81.80.060
Severability-1967 c 69: See note following RCW 81.80.010.