Except as otherwise provided in this section, the 1950 Tacoma Narrows bridge hereinbefore by the provisions of RCW
47.17.065 and
47.56.270 made a part of the primary state highways of the state shall be operated and maintained by the department as a toll-free facility at such time as the bonded indebtedness relating to the construction of the 1950 Tacoma Narrows bridge is wholly retired and tolls equaling the indebtedness of the toll bridge authority incurred for the construction of the 1950 Tacoma Narrows bridge to the county of Pierce have been collected. Toll charges may be imposed upon the 1950 Tacoma Narrows bridge only if that bridge is included as part of a public toll bridge facility that includes an additional toll bridge adjacent to the 1950 Tacoma Narrows bridge and constructed under RCW
47.46.080.