Nebraska Revised Statute 14-394
The city is authorized to change the grade of any street, boulevard, highway, main thoroughfare, controlled-access facility, connecting link, major traffic street, alley, or part thereof when a petition for a proper and satisfactory change of grade has been signed and filed by the record owners of a majority of the frontage of taxable property abutting upon that part of the street of which the change of grade is proposed. A petition for the order changing the grade may include the change of grade of any number of intersecting or connecting streets which may be reasonably appropriate and necessary to a proper adjustment of grades. In such event the sufficiency of the petition shall be determined by a consideration of the total frontage feet of taxable property upon all the streets or parts thereof upon which it is proposed to change the grades.
Laws 1959, c. 36, § 11, p. 200.