(a) An amount of not less than three-eighths of one percent nor more than one percent of the total yearly state and federal matching sum combined, under the federal-aid highways program (23 U.S.C.), shall be appropriated annually from the general fund to the department for the purposes of providing grants to eligible cities and boroughs for trails, footpaths, and shelter construction and maintenance in appropriate areas, including but not limited to existing park and recreation areas and for the purpose of providing grants to the Department of Transportation and Public Facilities for developing the program specified in AS 41.21.864(b) and 41.21.866.
(b) Except as provided in (c) of this section, the sums appropriated under this section shall continue to be available for expenditure by the departments or by eligible cities and boroughs for a period of three years after the close of the fiscal year for which the sums are authorized, unless they are obligated for expenditure, in which case they shall remain available until spent. Any amounts not obligated remaining unexpended at the end of the three-year period lapse.
(c) The amount expended by a city or borough under AS 41.21.864(a) or by the Department of Transportation and Public Facilities under AS 41.21.864(b) and 41.21.866, may not in any one fiscal year be less than 10 percent of the total amount of the funds it receives in that year for the purposes authorized in AS 41.21.864 - 41.21.872.