Funds made available under subsection (a) of section 104 of this title may be used to pay the entire engineering costs of the surveys, plans, specifications, estimates, and supervision of construction of projects for such urgent improvements of highways strategically important from the standpoint of the national defense as may be undertaken on the order of the Secretary and as the result of request of the Secretary of Defense or such other official as the President may designate. With the consent of a State, funds made available under subsection (b) of section 104 of this title may be used to the extent deemed necessary and advisable by the Secretary to carry out the provisions of this section.
23 U.S. Code § 311 - Highway improvements strategically important to the national defense
Statutory Notes and Related Subsidiaries
National Defense Highways Located Outside United States
“(1) Reconstruction projects.—
If the Secretary determines, after consultation with the Secretary of Defense, that a highway, or portion of a highway, located outside the United States is important to the national defense, the Secretary may carry out a project for the reconstruction of such highway or portion of highway.
The Secretary may make available, from funds appropriated to construct the National System of Interstate and Defense Highways, not to exceed $20,000,000 per fiscal year for each of fiscal years 1993, 1994, 1995, and 1996 to carry out this subsection. Such sums shall remain available until expended.”