(A) Whenever the Department of Transportation determines, upon the basis of an engineering and traffic investigation, that any maximum speed limit is greater or less than is reasonable or safe under the conditions found to exist at any intersection, place, or part of the state highway system outside of the corporate limits of cities and villages, as well as inside the corporate limits of cities and villages on freeways which are part of the state highway system, it may determine and set a reasonable and safe maximum speed limit for such intersection, place, or part of such highway, which shall be the lawful speed limit when appropriate signs giving notice thereof are erected at such intersection, place, or part of the highway, except that the maximum rural and freeway limits shall not be exceeded. Such a maximum speed limit may be set to be effective at all times or at such times as are indicated upon such signs.
(B) On all highways within its corporate limits, except on state-maintained freeways which are part of the state highway system, the City Council shall have the same power and duty to alter the maximum speed limits as the Department if the change is based on engineering and traffic investigation, except that no imposition of speed limits on highways which are part of the state highway system in the city shall be effective without the approval of the Department.
(C) Not more than six such speed limits shall be set per mile along a highway, except in the case of reduced limits at intersections, and the difference between adjacent limits shall not be more than 20 mph, and there shall be no limit on the difference between adjacent speed limits for increasing speed limits along a highway.
(D) When the Department or the City Council determines by an investigation that certain vehicles in addition to those specified in Neb. RS 60-6,187, 60-6,305, and 60-6,313 cannot with safety travel at the speeds provided in §§ 71.21 and 71.22 and Neb. RS 60-6,187, 60-6,305, and 60-6,313, or set pursuant to this section, § 71.22, or Neb. RS 60-6,188, the Department or the City Council may restrict the speed limit for such vehicles on highways under its respective jurisdiction and post proper and adequate signs.
(Neb. RS 60-6,190)