Wash. Rev. Code § 81.75.030
To the extent feasible, the services available to the public at any transportation center may include taxi, auto rental, passenger trains, motor buses, travel agents, restrooms, food, telegraph, baggage handling, transfer and delivery of light freight and packages, commercial airlines, air charter, place of temporary rest for citizens and travelers (but not overnight), mail, private auto parking for users of public transportation through the transportation center, local transit, limousine, and any other use necessary to the foregoing.
Any city, town, county, public transportation benefit area authority, or municipal corporation, which elects to operate a transportation center shall operate the center for the general public good. The operator may establish the terms of usage for the various modes of transportation and for others that utilize its facilities, may make reasonable rules concerning public and private use, and may exclude all persons therefrom who refuse to comply with the terms or rules of use. The operator may own, operate, maintain, and manage a transportation center, but shall not engage in providing a transportation or other related service at the center unless otherwise authorized by law.
RCW 81.75.030