23 U.S.C. §129 and RCW 47.04.140 require that counties operating ferries which receive federal aid under Title 23 of the United States Code must obtain from the department a franchise authorizing such ferry operations and approving their tolls. RCW 47.56.720 and 47.56.725 permit the department to enter into continuing agreements to provide financial assistance for counties operating ferries. The purpose of this chapter is to provide procedures for the granting of such franchises and the provision of such financial assistance.