Neb. Rev. Stat. §§ 39-1305
The department shall have the authority to make all contracts and do all things necessary to cooperate with the United States Government in matters relating to the cooperative construction or improvement of the state highway system, or any road or street of any political or governmental subdivision or any public corporation of this state, or of any road necessary to be constructed for national defense, national forests and scenic purposes, for which federal funds or aid are secured and for maintenance of roads constructed for the United States Government. Such contracts or acts shall be carried out in the manner required by the provisions of the acts of Congress and the rules and regulations made by an agent of the United States in pursuance of such acts.
Neb. Rev. Stat. §§ 39-1305