Washington Revised Code Title 81. Transportation § 81.80.120. Classification of carriers

The commission may from time to time establish such just and reasonable classifications of the groups of carriers included in the terms “common carriers” and “contract carriers” as the special nature of the services performed by such carriers shall require, and such just and reasonable rules, regulations and requirements, consistent with the provisions of this chapter, to be observed by the carriers so classified or grouped, as the commission deems necessary or advisable in the public interest.