N.H. Rev. Stat. § 235:4
The commissioner of transportation is authorized to act for the state or any of its political subdivisions in conjunction with the representatives of the federal government in all matters relating to the location and construction of highways, including flight strips, to be built with federal aid, to establish urban areas, and to take such action as may be necessary to secure to the state the aid and benefits of the provisions of said act and all amendments thereto, including the Federal-Aid Highway Act of 1944, and of the provisions of the Federal Highway Act of November 9, 1921, and all amendments thereto.
RSA 235:4
1917, 162:3. PL 88 :4. RL 104:4. 1945, 188:1, part 11:4. 1950, 5:1, part 9:1, par. 2. RSA 239:4. 1981, 87:1. 1985, 402:6, I(b)(6).