All moneys received from the federal government for road construction shall be expended as provided, or as may hereafter be provided by act of Congress.
If at the end of any annual period, any money in the reserve fund remains unexpended or unappropriated, it shall be placed in the general fund for reserve and distribution during the next annual period.
The remaining eighty percent, or, if such reserve fund is not set aside, then all the funds shall be appropriated in the following order and preference:
(1) For the construction, reconstruction, and maintenance of expressway and trunkline roads, and to comply with the requirements for the receipt of aid from the federal government;
(2) For the maintenance of all feeder and state local service roads, as provided in section six-a of this article;
(3) For the construction and reconstruction of feeder and state local service roads as prescribed in section six-a of this article.