Wash. Rev. Code § 81.28.040
Every common carrier subject to regulation by the commission as to rates and service shall file with the commission and shall print and keep open for public inspection, schedules showing the rates, fares, charges, and classification for the transportation of persons and property within the state between each point upon the carrier's route and all other points thereon; and between each point upon its route and all points upon every route leased, operated, or controlled by it; and between each point on its route or upon any route leased, operated, or controlled by it and all points upon the route of any other common carrier, whenever a through route and joint rate have been established or ordered between any two such points. If no joint rate over a through route has been established, the several carriers participating in the through route shall file, print, and keep open for public inspection, the separately established rates, fares, charges, and classifications that apply to the through transportation. The schedules printed must: Plainly state the places between which property and persons are carried; contain classification of passengers or property in force; and state separately all terminal charges, storage charges, icing charges, all other charges that the commission may require to be stated, all privileges or facilities granted or allowed, and any rules or regulations that may in any way change, affect, or determine any part, or the aggregate of, such rates, fares, and charges, or the value of the service rendered to the passenger, shipper, or consignee. The schedule must be plainly printed in large type, and a copy of it shall be kept by every carrier readily accessible to inspection by the public in every station or office of the carrier where passengers or property are respectively received for transportation, when the station or office is in charge of any agent. All of the schedules kept as provided in this section must be immediately produced by the carrier for inspection upon the demand of any person. A notice printed in bold type and stating that the schedules are on file with the agent and open to inspection by any person and that the agent will assist any person to determine from the schedules any transportation rates or fares or rules or regulations that are in force must be kept posted by the carrier in two public and conspicuous places in every such station or office. The form of each schedule must be prescribed by the commission.
The commission may, from time to time, determine and prescribe by order such changes in the form of the schedules as may be found expedient, and modify the requirements of this section in respect to publishing, posting, and filing of schedules either in particular instances or by general rule or order applicable to special or peculiar circumstances or conditions.
The commission may suspend the operation of this section in whole or in part as applied to vessels engaged in jobbing business not operating on regular routes.
RCW 81.28.040