(a) In the development and maintenance of the state highway system, the commission shall provide for the:
(1) efficient maintenance of the system;
(2) construction, in cooperation with the United States to the extent of federal aid to the state, of durable highways of the greatest public necessity;
(3) construction of highways to perfect and extend a correlated system of state highways, independently from state funds; and
(4) construction of highways to provide access to significant new naval military facilities and to provide for the state highway system in impacted regions.
(b) Subsection (a) shall be implemented from funds available to the department except that Subsection (a)(4) shall be implemented only from the state highway fund.
(c) In this section, "significant new naval military facility" and "impacted region" have the meanings assigned by Section 4, Article 1, National Defense Impacted Region Assistance Act of 1985 (Article 689a-4d, Vernon's Texas Civil Statutes).