1. No vehicle or combination of vehicles shall be moved or operated on any highway in this state having a greater weight than twenty thousand pounds on one axle, no combination of vehicles operated by transporters of general freight over regular routes as defined in section 390.020 shall be moved or operated on any highway of this state having a greater weight than the vehicle manufacturer's rating on a steering axle with the maximum weight not to exceed twelve thousand pounds on a steering axle, and no vehicle shall be moved or operated on any state highway of this state having a greater weight than thirty-four thousand pounds on any tandem axle; the term "tandem axle" shall mean a group of two or more axles, arranged one behind another, the distance between the extremes of which is more than forty inches and not more than ninety-six inches apart.
2. An "axle load" is defined as the total load transmitted to the road by all wheels whose centers are included between two parallel transverse vertical planes forty inches apart, extending across the full width of the vehicle.
3. Subject to the limit upon the weight imposed upon a highway of this state through any one axle or on any tandem axle, the total gross weight with load imposed by any group of two or more consecutive axles of any vehicle or combination of vehicles shall not exceed the maximum load in pounds as set forth in the following table:
4. Whenever the state highways and transportation commission finds that any state highway bridge in the state is in such a condition that use of such bridge by vehicles of the weights specified in subsection 3 of this section will endanger the bridge, or the users of the bridge, the commission may establish maximum weight limits and speed limits for vehicles using such bridge. The governing body of any city or county may grant authority by act or ordinance to the commission to enact the limitations established in this section on those roadways within the purview of such city or county. Notice of the weight limits and speed limits established by the commission shall be given by posting signs at a conspicuous place at each end of any such bridge.
5. Nothing in this section shall be construed as permitting lawful axle loads, tandem axle loads or gross loads in excess of those permitted under the provisions of P.L. 97-424 codified in Title 23 of the United States Code (23 U.S.C. Section 101, et al.), as amended.
6. Notwithstanding the weight limitations contained in this section, any vehicle or combination of vehicles operating on highways other than the interstate highway system may exceed single axle, tandem axle and gross weight limitations in an amount not to exceed two thousand pounds. However, total gross weight shall not exceed eighty thousand pounds, except as provided in subsections 9, 10, 12, 13, and 14 of this section.
7. Notwithstanding any provision of this section to the contrary, the commission shall issue a single-use special permit, or upon request of the owner of the truck or equipment shall issue an annual permit, for the transporting of any crane or concrete pump truck or well-drillers' equipment. The commission shall set fees for the issuance of permits and parameters for the transport of cranes pursuant to this subsection. Notwithstanding the provisions of section 301.133 , cranes, concrete pump trucks, or well-drillers' equipment may be operated on state-maintained roads and highways at any time on any day.
8. Notwithstanding the provision of this section to the contrary, the maximum gross vehicle limit and axle weight limit for any vehicle or combination of vehicles equipped with an idle reduction technology may be increased by a quantity necessary to compensate for the additional weight of the idle reduction system as provided for in 23 U.S.C. Section 127, as amended. In no case shall the additional weight increase allowed by this subsection be greater than five hundred fifty pounds. Upon request by an appropriate law enforcement officer, the vehicle operator shall provide proof that the idle reduction technology is fully functional at all times and that the gross weight increase is not used for any purpose other than for the use of idle reduction technology.
9. Notwithstanding any provision of this section or any other law to the contrary, the total gross weight of any vehicle or combination of vehicles hauling milk from a farm to a processing facility or livestock may be as much as, but shall not exceed, eighty-five thousand five hundred pounds while operating on highways other than the interstate highway system. The provisions of this subsection shall not apply to vehicles operated and operating on the Dwight D. Eisenhower System of Interstate and Defense Highways.
10. Notwithstanding any provision of this section or any other law to the contrary, any vehicle or combination of vehicles hauling grain or grain coproducts during times of harvest may be as much as, but not exceeding, ten percent over the maximum weight limitation allowable under subsection 3 of this section while operating on highways other than the interstate highway system. The provisions of this subsection shall not apply to vehicles operated and operating on the Dwight D. Eisenhower System of Interstate and Defense Highways.
11. Notwithstanding any provision of this section or any other law to the contrary, the commission shall issue emergency utility response permits for the transporting of utility wires or cables, poles, and equipment needed for repair work immediately following a disaster where utility service has been disrupted. Under exigent circumstances, verbal approval of such operation may be made either by the department of transportation motor carrier compliance supervisor or other designated motor carrier services representative. Utility vehicles and equipment used to assist utility companies granted special permits under this subsection may be operated and transported on state-maintained roads and highways at any time on any day. The commission shall promulgate all necessary rules and regulations for the administration of this section. Any rule or portion of a rule, as that term is defined in section 536.010 , that is created under the authority delegated in this section shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028 . This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date, or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after August 28, 2014, shall be invalid and void.
12. Notwithstanding any provision of this section to the contrary, emergency vehicles designed to be used under emergency conditions to transport personnel and equipment and to support the suppression of fires and mitigate hazardous situations may have a maximum gross vehicle weight of eighty-six thousand pounds inclusive of twenty-four thousand pounds on a single steering axle; thirty-three thousand five hundred pounds on a single drive axle; sixty-two thousand pounds on a tandem axle; or fifty-two thousand pounds on a tandem rear-drive steer axle; except that, such emergency vehicles shall only operate on the Dwight D. Eisenhower National System of Interstate and Defense Highways.
13. Notwithstanding any provision of this section to the contrary, a vehicle operated by an engine fueled primarily by natural gas may operate upon the public highways of this state in excess of the vehicle weight limits set forth in this section by an amount that is equal to the difference between the weight of the vehicle attributable to the natural gas tank and fueling system carried by that vehicle and the weight of a comparable diesel tank and fueling system. In no event shall the maximum gross vehicle weight of the vehicle operating with a natural gas engine exceed eighty-two thousand pounds.
14. Notwithstanding any provision of law to the contrary, local log trucks and local log truck tractors, as defined in section 301.010 , may be operated with a weight not exceeding twenty-two thousand four hundred pounds on one axle or a weight not exceeding forty-four thousand eight hundred pounds on any tandem axle, except the front steering axle shall not exceed fifteen thousand pounds or the gross vehicle weight rating set by the manufacturer, and may have a total weight of up to one hundred nine thousand six hundred pounds. Provided however, when operating on the national system of interstate and defense highways described in 23 U.S.C. Section 103, as amended, or outside the radius from the forested site specified in section 301.010 with an extended distance local log truck permit, the vehicle shall not exceed the weight limits otherwise specified in this section.