(625 ILCS 5/15-112) (from Ch. 95 1/2, par. 15-112)
    Sec. 15-112. Officers to weigh vehicles and require removal of excess loads.
    (a) Any police officer having reason to believe that the weight of a vehicle and load is unlawful shall require the driver to stop and submit to a weighing of the same either by means of a portable or stationary scales that have been tested and approved at a frequency prescribed by the Illinois Department of Agriculture, or for those scales operated by the State, when such tests are requested by the Illinois State Police, whichever is more frequent. If such scales are not available at the place where such vehicle is stopped, the police officer shall require that such vehicle be driven to the nearest available scale that has been tested and approved pursuant to this Section by the Illinois Department of Agriculture. Notwithstanding any provisions of the Weights and Measures Act or the United States Department of Commerce NIST handbook 44, multi or single draft weighing is an acceptable method of weighing by law enforcement for determining a violation of Chapter 3 or 15 of this Code. Law enforcement is exempt from the requirements of commercial weighing established in NIST handbook 44.
    Within 18 months after the effective date of this amendatory Act of the 91st General Assembly, all municipal and county officers, technicians, and employees who set up and operate portable scales for wheel load or axle load or both and issue citations based on the use of portable scales for wheel load or axle load or both and who have not successfully completed initial classroom and field training regarding the set up and operation of portable scales, shall attend and successfully complete initial classroom and field training administered by the Illinois Law Enforcement Training Standards Board.
    (b) Whenever an officer, upon weighing a vehicle and the load, determines that the weight is unlawful, such officer shall require the driver to stop the vehicle in a suitable place and remain standing until such portion of the load is removed as may be necessary to reduce the weight of the vehicle to the limit permitted under this Chapter, or to the limit permitted under the terms of a permit issued pursuant to Sections 15-301 through 15-318 and shall forthwith arrest the driver or owner. All material so unloaded shall be cared for by the owner or operator of the vehicle at the risk of such owner or operator; however, whenever a 3 or 4 axle vehicle with a tandem axle dimension greater than 72 inches, but less than 96 inches and registered as a Special Hauling Vehicle is transporting asphalt or concrete in the plastic state that exceeds axle weight or gross weight limits by less than 4,000 pounds, the owner or operator of the vehicle shall accept the arrest ticket or tickets for the alleged violations under this Section and proceed without shifting or reducing the load being transported or may shift or reduce the load under the provisions of subsection (d) or (e) of this Section, when applicable. Any fine imposed following an overweight violation by a vehicle registered as a Special Hauling Vehicle transporting asphalt or concrete in the plastic state shall be paid as provided in subsection 4 of paragraph (a) of Section 16-105 of this Code.
    (c) The Department of Transportation may, at the request of the Illinois State Police, erect appropriate regulatory signs on any State highway directing second division vehicles to a scale. The Department of Transportation may also, at the direction of any State Police officer, erect portable regulating signs on any highway directing second division vehicles to a portable scale. Every such vehicle, pursuant to such sign, shall stop and be weighed.
    (d) Whenever any axle load of a vehicle exceeds the axle or tandem axle weight limits permitted by paragraph (a) of Section 15-111 by 2000 pounds or less, the owner or operator of the vehicle must shift or remove the excess so as to comply with paragraph (a) of Section 15-111. No overweight arrest ticket shall be issued to the owner or operator of the vehicle by any officer if the excess weight is shifted or removed as required by this paragraph.
    (e) Whenever the gross weight of a vehicle with a registered gross weight of 77,000 pounds or less exceeds the weight limits of paragraph (a) of Section 15-111 of this Chapter by 2000 pounds or less, the owner or operator of the vehicle must remove the excess. Whenever the gross weight of a vehicle with a registered gross weight over 77,000 pounds or more exceeds the weight limits of paragraph (a) of Section 15-111 by 1,000 pounds or less or 2,000 pounds or less if weighed on wheel load weighers, the owner or operator of the vehicle must remove the excess. In either case no arrest ticket for any overweight violation of this Code shall be issued to the owner or operator of the vehicle by any officer if the excess weight is removed as required by this paragraph. A person who has been granted a special permit under Section 15-301 of this Code shall not be granted a tolerance on wheel load weighers.
    (e-5) Auxiliary power or idle reduction unit (APU) weight.
        (1) A vehicle with a fully functional APU shall be
    
allowed an additional 550 pounds or the certified unit weight, whichever is less. The additional pounds may be allowed in gross, axles, or bridge formula weight limits above the legal weight limits except when overweight on an axle or axles of the towed unit or units in combination. This tolerance shall be given in addition to the limits in subsection (d) of this Section.
        (2) An operator of a vehicle equipped with an APU
    
shall carry written certification showing the weight of the APU, which shall be displayed upon the request of any law enforcement officer.
        (3) The operator may be required to demonstrate or
    
certify that the APU is fully functional at all times.
        (4) This allowance may not be granted above the
    
weight limits specified on any loads permitted under Section 15-301 of this Code.
    (f) Whenever an axle load of a vehicle exceeds axle weight limits allowed by the provisions of a permit an arrest ticket shall be issued, but the owner or operator of the vehicle may shift the load so as to comply with the provisions of the permit. Where such shifting of a load to comply with the permit is accomplished, the owner or operator of the vehicle may then proceed.
    (g) Any driver of a vehicle who refuses to stop and submit his vehicle and load to weighing after being directed to do so by an officer or removes or causes the removal of the load or part of it prior to weighing is guilty of a business offense and shall be fined not less than $500 nor more than $2,000.
(Source: P.A. 102-538, eff. 8-20-21.)