Such ferry system, including any toll bridges, approaches, and roadways incidental thereto, may be financed and operated in combination or separately as one or more units as the department of transportation may determine, and such ferry system together with any toll bridge hereafter constructed by the department upon or across the waters of Puget Sound or Hood Canal, or any part of either, replacing one or more presently operated ferry routes, is declared to be a continuous project within the meaning of *RCW
47.56.070. The department is empowered to rent, lease, or charter any property acquired under this chapter. If the department determines that any real property (including lands, improvements thereon, and any interests or estates) originally acquired for the ferry system is no longer required for the purposes of the ferry system, the department shall offer it for sale in the manner and with the authority authorized to the department by RCW
47.12.063 or
47.12.283. The secretary of transportation may adopt rules further implementing this section. The proceeds of all such sales shall be paid into the separate trust fund of the state treasury established pursuant to **RCW
47.60.150.