Wash. Rev. Code § 47.06.010
The legislature recognizes that the ownership and operation of Washington's transportation system is spread among federal, state, and local government agencies, regional transit agencies, port districts, and the private sector. The legislature also recognizes that transportation planning authority is shared on the local, regional, and state levels, and that this planning must be a comprehensive and coordinated effort. While significant authority for transportation planning is vested with local agencies and regional transportation planning organizations under the growth management act, the legislature recognizes that certain transportation issues and facilities cross local and regional boundaries and are vital to the statewide economy and the cross-state mobility of people and goods. Therefore, the state has an appropriate role in developing statewide transportation plans that address state jurisdiction facilities and services as well as transportation facilities and services of state interest. These plans shall serve as a guide for short-term investment needs and provide a long-range vision for transportation system development.
RCW 47.06.010