Neb. Rev. Stat. § 39-8,109

The funds available to the department under the provisions of sections 39-891 to 39-8,122 may be used by the department in support of any interstate bridge construction or maintenance agreement; Provided, that such agreement shall contain provisions which insure that the state performing construction or maintenance, or letting construction or maintenance contracts, pursuant to the agreement shall be reimbursed by the nonperforming state in a percentage of the total construction or maintenance costs equal to the proportion of the agreed construction or maintenance area within the nonperforming state.