(a) Commencing with appropriations for the fiscal year that begins July 1, 1991, on an annual basis and under AS 37.07 (Executive Budget Act), the legislature may appropriate amounts from the Alaska marine highway system fund to the Alaska marine highway system.
(b) The Department of Transportation and Public Facilities may request the legislature to appropriate money from the Alaska marine highway system fund to the marine highway system for capital improvements, if
(1) the appropriation under (a) of this section has been made;
(2) the amount in the fund, without regard to the appropriation under (a) of this section, exceeds the total of gross revenue deposited in the fund and the general fund appropriations under AS 19.65.060 (a)(2) by 10 percent; and
(3) the amount requested for appropriation under this subsection does not exceed 50 percent of the balance remaining after the appropriation for annual management and operations is made under (a) of this section.
(c) The unexpended and unobligated balance of money appropriated from the Alaska marine highway system fund lapses into the Alaska marine highway system fund at the end of the fiscal year for which it was appropriated.