A.    Definitions: As used in this section, the following terms shall have the meanings ascribed to them:
   SINGLE AXLE: Includes all wheels whose centers may be included within two (2) parallel transverse vertical planes forty inches (40") apart.
   VEHICLE: Includes all motor vehicles, trucks, commercial vehicles, horse trailers and trailers of all kinds, or any object or contrivance being moved on wheels of any kind. (1974 Code § 1305.03)
   B.    Authority; Signs Posted: The engineer may prohibit the operation of vehicles upon any street or highway within the city or impose restrictions as to the weight of vehicles to be operated thereon whenever any such streets or highway, by reason of deterioration, rain, snow or other climatic conditions, will be seriously damaged or destroyed unless the use of such vehicles thereon is prohibited or the permissible weights thereof reduced. The engineer shall erect or cause to be erected and maintained signs plainly indicating the prohibition or restriction at each end of that portion of any street or highway affected thereby. Said prohibition or restriction shall not be effective unless and until such signs are erected and shall continue thereafter until the engineer causes such signs to be removed.
   C.    Weight Limit During Certain Time Of Year: Except where other restrictions are imposed as provided in subsection B of this section, no person shall operate any vehicle or combination of vehicles upon any street, road, or highway under the jurisdiction of the city during the period between March 20 and May 15 of each year, where the gross weight on any single axle exceeds eight thousand (8,000) pounds; provided, that there shall be excepted and exempt from the provisions of this subsection emergency vehicles of public utilities used incidental to making repairs to its plant or equipment, and this subsection shall not apply to routes, streets or highways designated by resolution of the council as truck routes and which are identified as such by signs and markings to that effect.
   D.    Special Permit: For reasons of hardship or other good cause shown, a special permit may be issued by the engineer authorizing vehicles which would otherwise be prohibited under the provisions of subsection C of this section from traveling over certain streets, roads or highways to travel over such streets, roads or highways on a prescribed route for the purpose of making deliveries to a home or commercial or industrial establishment. Such permit may be conditioned upon the giving of security in sufficient amount to compensate the city for any injury or damage to any street, road or highway caused by the operation of such vehicle or combination of vehicles thereon. (1974 Code § 1305.01)