According to 
Washington State Policy, the state has a broad interest in all modes of transportation because of the benefits they bring to its citizens. For modes such as public transportation and aviation, the state government’s authority is limited, since these facilities are typically owned and operated by others. Nevertheless, the state still has interest that is carried out by the owners of these systems.
WSDOT has a role in advocating for preservation of aviation facilities, safe air transportation, airport capacity to meet demand, and mitigation of environment impacts. The state’s authority in meeting this interest is achieved primarily through advocacy and partnership.
WSDOT Aviation's planning program provides technical resources and uses a cooperative approach to work with airports, communities, planning organizations and local decision makers to set a policy direction for the aviation system. The objective is to ensure the viability and adequacy of air transportation for the state and its citizens.
WSDOT Aviation's planning responsibilities include: