Neb. Rev. Stat. §§ 17-512
The city council of a city of the second class or village board of trustees may, by a three-fourths vote of all members of such city council or village board of trustees, enact an ordinance creating an improvement district, order such work to be done without petition upon any federal or state highways in the city or village or upon a street or route, designated by the mayor and city council or village board of trustees as a main thoroughfare, that connects to either a federal or state highway or a county road, and shall contract for such work, and shall levy assessments on the lots and parcels of land abutting on or adjacent to such street or alley specially benefited thereby in such district in proportion to such benefits, to pay the cost of such improvement.
Neb. Rev. Stat. §§ 17-512