Except as otherwise provided in RCW 47.56.850, the secretary shall have full charge of the construction of all such improvements and reconstruction work and the construction of any additional bridge, including approaches and connecting highways, that may be authorized under this chapter and the operation of such bridge or bridges, as well as the collection of tolls and other charges for services and facilities thereby afforded. The schedule of charges for the services and facilities shall be fixed and revised from time to time by the commission so that the tolls and revenues collected will yield annual revenue and income sufficient, after payment or allowance for all operating, maintenance, and repair expenses, to pay the interest on all revenue bonds outstanding under the provisions of this chapter for account of the project and to create a sinking fund for the retirement of the revenue bonds at or prior to maturity. The charges shall be continued until all such bonds and interest thereon and unpaid advancements, if any, have been paid.