The toll facilities revenue bond redemption fund is established for deposit in trust of money for paying and securing the payment of principal of and interest and redemption premium, if any, on bonds and is set apart from all other money of the state. The committee, on behalf of the state, shall obligate the state to set aside and pay into the bond redemption fund from the revenue fund an amount of money sufficient to pay the principal of and interest and redemption premium, if any, on the bonds as the payments become due and, if the committee considers it necessary, to set aside and maintain a reserve for this purpose. The bond redemption fund is drawn upon for the purpose of paying the principal of and interest and redemption premium, if any, on the bonds, and the bonds do not constitute a general obligation of the state.