625 ILCS 5/ Illinois Vehicle Code.

(625 ILCS 5/15-110) (from Ch. 95 1/2, par. 15-110)

Sec. 15-110. Towed vehicles.

(a) When one vehicle is towing another, the drawbar or other connection shall be of sufficient strength to pull all the weight towed thereby and the drawbar or other connection shall not exceed 15 feet from one vehicle to the other, except for the connection between any 2 vehicles transporting poles, pipes, machinery or other objects of structural nature which cannot readily be dismembered.

(b) Outside a business, residential or suburban district or on any controlled access highway, no vehicle other than a pole trailer or a semitrailer which is being towed by a truck tractor and is connected by the means of a fifth wheel shall be towed on a roadway except by a drawbar and each such vehicle so towed shall, in addition, be coupled with 2 safety chains or cables to the towing vehicle. Such chains or cables shall be of sufficient size and strength to prevent the towed vehicle parting from the drawing vehicle in case the drawbar should break or become disengaged.

(c) The provisions of this section shall not apply to any second division vehicle owned, operated or controlled by any person who is registered with the Bureau of Motor Carrier Safety of the Federal Highway Administration and has complied with the federal safety provisions of the Bureau of Motor Carrier Safety of the Federal Highway Administration and the rules and regulations of the Bureau.

(Source: P.A. 77-22.)

(625 ILCS 5/15-111) (from Ch. 95 1/2, par. 15-111)

Sec. 15-111. Wheel and axle loads and gross weights.

(a) No vehicle or combination of vehicles with pneumatic tires may be operated, unladen or with load, when the total weight on the road surface exceeds the following: 20,000 pounds on a single axle; 34,000 pounds on a tandem axle with no axle within the tandem exceeding 20,000 pounds; 80,000 pounds gross weight for vehicle combinations of 5 or more axles; or a total weight on a group of 2 or more consecutive axles in excess of that weight produced by the application of the following formula: W = 500 times the sum of (LN divided by N-1) + 12N + 36, where "W" equals overall total weight on any group of 2 or more consecutive axles to the nearest 500 pounds, "L" equals the distance measured to the nearest foot between extremes of any group of 2 or more consecutive axles, and "N" equals the number of axles in the group under consideration.

The above formula when expressed in tabular form results in allowable loads as follows:

Distance measured

to the nearest

foot between the

extremes of any Maximum weight in pounds

group of 2 or of any group of

more consecutive 2 or more consecutive axles

axles

*If the distance between 2 axles is 96 inches or less, the 2 axles are tandem axles and the maximum total weight may not exceed 34,000 pounds, notwithstanding the higher limit resulting from the application of the formula.

**Two consecutive sets of tandem axles may carry 34,000 pounds each if the overall distance between the first and last axles of these tandems is 36 feet or more.

Vehicles not in a combination having more than 4 axles may not exceed the weight in the table in this subsection (a) for 4 axles measured between the extreme axles of the vehicle.

Vehicles in a combination having more than 6 axles may not exceed the weight in the table in this subsection (a) for 6 axles measured between the extreme axles of the combination.

Local authorities, with respect to streets and highways under their jurisdiction, without additional fees, may also by ordinance or resolution allow the weight limitations of this subsection, provided the maximum gross weight on any one axle shall not exceed 20,000 pounds and the maximum total weight on any tandem axle shall not exceed 34,000 pounds, on designated highways when appropriate regulatory signs giving notice are erected upon the street or highway or portion of any street or highway affected by the ordinance or resolution.

The following are exceptions to the above formula:

(1) Vehicles for which a different limit is established and posted in accordance with Section 15-316 of this Code.

(2) Vehicles for which the Department of Transportation and local authorities issue overweight permits under authority of Section 15-301 of this Code. These vehicles are not subject to the bridge formula.

(3) Cities having a population of more than 50,000 may permit by ordinance axle loads on 2-axle motor vehicles 33 1/2% above those provided for herein, but the increase shall not become effective until the city has officially notified the Department of the passage of the ordinance and shall not apply to those vehicles when outside of the limits of the city, nor shall the gross weight of any 2-axle motor vehicle operating over any street of the city exceed 40,000 pounds.

(4) Weight limitations shall not apply to vehicles (including loads) operated by a public utility when transporting equipment required for emergency repair of public utility facilities or properties or water wells.

(4.5) A 3-axle or 4-axle vehicle (including when laden) operated or hired by a municipality within Cook, Lake, McHenry, Kane, DuPage, or Will county being operated for the purpose of performing emergency sewer repair that would be subject to a weight limitation less than 66,000 pounds under the formula in this subsection (a) shall have a weight limitation of 66,000 pounds or the vehicle's gross vehicle weight rating, whichever is less. This paragraph (4.5) does not apply to vehicles being operated on the National System of Interstate and Defense Highways, or to vehicles being operated on bridges or other elevated structures constituting a part of a highway.

(5) Two consecutive sets of tandem axles may carry a total weight of 34,000 pounds each if the overall distance between the first and last axles of the consecutive sets of tandem axles is 36 feet or more, notwithstanding the lower limit resulting from the application of the above formula.

(6) A truck, not in combination and used exclusively for the collection of rendering materials, may, when laden, transmit upon the road surface, except when on part of the National System of Interstate and Defense Highways, the following maximum weights: 22,000 pounds on a single axle; 40,000 pounds on a tandem axle.

(7) A truck not in combination, equipped with a self compactor or an industrial roll-off hoist and roll-off container, used exclusively for garbage, refuse, or recycling operations, may, when laden, transmit upon the road surface, except when on part of the National System of Interstate and Defense Highways, the following maximum weights: 22,000 pounds on a single axle; 40,000 pounds on a tandem axle; 40,000 pounds gross weight on a 2-axle vehicle; 54,000 pounds gross weight on a 3-axle vehicle. This vehicle is not subject to the bridge formula.

(7.5) A 3-axle rear discharge truck mixer registered as a Special Hauling Vehicle, used exclusively for the mixing and transportation of concrete in the plastic state, may, when laden, transmit upon the road surface, except when on part of the National System of Interstate and Defense Highways, the following maximum weights: 22,000 pounds on single axle; 40,000 pounds on a tandem axle; 54,000 pounds gross weight on a 3-axle vehicle. This vehicle is not subject to the bridge formula.

(8) Except as provided in paragraph (7.5) of this subsection (a), tandem axles on a 3-axle truck registered as a Special Hauling Vehicle, manufactured prior to or in the model year of 2024 and first registered in Illinois prior to January 1, 2025, with a distance greater than 72 inches but not more than 96 inches between any series of 2 axles, is allowed a combined weight on the series not to exceed 36,000 pounds and neither axle of the series may exceed 20,000 pounds. Any vehicle of this type manufactured after the model year of 2024 or first registered in Illinois after December 31, 2024 may not exceed a combined weight of 34,000 pounds through the series of 2 axles and neither axle of the series may exceed 20,000 pounds.

A 3-axle combination sewer cleaning jetting vacuum truck registered as a Special Hauling Vehicle, used exclusively for the transportation of non-hazardous solid waste, manufactured before or in the model year of 2014, first registered in Illinois before January 1, 2015, may, when laden, transmit upon the road surface, except when on part of the National System of Interstate and Defense Highways, the following maximum weights: 22,000 pounds on a single axle; 40,000 pounds on a tandem axle; 54,000 pounds gross weight on a 3-axle vehicle. This vehicle is not subject to the bridge formula.

(9) A 4-axle truck mixer registered as a Special Hauling Vehicle, used exclusively for the mixing and transportation of concrete in the plastic state, and not operated on a highway that is part of the National System of Interstate Highways, is allowed the following maximum weights: 20,000 pounds on any single axle; 36,000 pounds on a series of axles greater than 72 inches but not more than 96 inches; and 34,000 pounds on any series of 2 axles greater than 40 inches but not more than 72 inches. The gross weight of this vehicle may not exceed the weights allowed by the bridge formula for 4 axles. The bridge formula does not apply to any series of 3 axles while the vehicle is transporting concrete in the plastic state, but no axle or tandem axle of the series may exceed the maximum weight permitted under this paragraph (9) of subsection (a).

(10) Combinations of vehicles, registered as Special Hauling Vehicles that include a semitrailer manufactured prior to or in the model year of 2024, and registered in Illinois prior to January 1, 2025, having 5 axles with a distance of 42 feet or less between extreme axles, may not exceed the following maximum weights: 20,000 pounds on a single axle; 34,000 pounds on a tandem axle; and 72,000 pounds gross weight. This combination of vehicles is not subject to the bridge formula. For all those combinations of vehicles that include a semitrailer manufactured after the effective date of P.A. 92-0417, the overall distance between the first and last axles of the 2 sets of tandems must be 18 feet 6 inches or more. Any combination of vehicles that has had its cargo container replaced in its entirety after December 31, 2024 may not exceed the weights allowed by the bridge formula.

(11) The maximum weight allowed on a vehicle with crawler type tracks is 40,000 pounds.

(12) A combination of vehicles, including a tow truck and a disabled vehicle or disabled combination of vehicles, that exceeds the weight restriction imposed by this Code, may be operated on a public highway in this State provided that neither the disabled vehicle nor any vehicle being towed nor the tow truck itself shall exceed the weight limitations permitted under this Chapter. During the towing operation, neither the tow truck nor the vehicle combination shall exceed 24,000 pounds on a single rear axle and 44,000 pounds on a tandem rear axle, provided the towing vehicle:

(i) is specifically designed as a tow truck having a gross vehicle weight rating of at least 18,000 pounds and is equipped with air brakes, provided that air brakes are required only if the towing vehicle is towing a vehicle, semitrailer, or tractor-trailer combination that is equipped with air brakes;

(ii) is equipped with flashing, rotating, or oscillating amber lights, visible for at least 500 feet in all directions;

(iii) is capable of utilizing the lighting and braking systems of the disabled vehicle or combination of vehicles; and

(iv) does not engage in a tow exceeding 20 miles from the initial point of wreck or disablement. Any additional movement of the vehicles may occur only upon issuance of authorization for that movement under the provisions of Sections 15-301 through 15-318 of this Code. The towing vehicle, however, may tow any disabled vehicle to a point where repairs are actually to occur. This movement shall be valid only on State routes. The tower must abide by posted bridge weight limits.

(12.5) The vehicle weight limitations in this Section do not apply to a covered heavy duty tow and recovery vehicle. The covered heavy duty tow and recovery vehicle license plate must cover the operating empty weight of the covered heavy duty tow and recovery vehicle only.

(13) Upon and during a declaration of an emergency propane supply disaster by the Governor under Section 7 of the Illinois Emergency Management Agency Act:

(i) a truck not in combination, equipped with a cargo tank, used exclusively for the transportation of propane or liquefied petroleum gas may, when laden, transmit upon the road surface, except when on part of the National System of Interstate and Defense Highways, the following maximum weights: 22,000 pounds on a single axle; 40,000 pounds on a tandem axle; 40,000 pounds gross weight on a 2-axle vehicle; 54,000 pounds gross weight on a 3-axle vehicle; and

(ii) a truck when in combination with a trailer equipped with a cargo tank used exclusively for the transportation of propane or liquefied petroleum gas may, when laden, transmit upon the road surface, except when on part of the National System of Interstate and Defense Highways, the following maximum weights: 22,000 pounds on a single axle; 40,000 pounds on a tandem axle; 90,000 pounds gross weight on a 5-axle or 6-axle vehicle.

Vehicles operating under this paragraph (13) are not subject to the bridge formula.

(14) A vehicle or combination of vehicles that uses natural gas or propane gas as a motor fuel may exceed the above weight limitations by up to 2,000 pounds, the total allowance is calculated by an amount that is equal to the difference between the weight of the vehicle attributable to the natural gas or propane gas tank and fueling system carried by the vehicle, and the weight of a comparable diesel tank and fueling system. This paragraph (14) shall not allow a vehicle to exceed any posted weight limit on a highway or structure.

(15) An emergency vehicle or fire apparatus that is a vehicle designed to be used under emergency conditions to transport personnel and equipment, and used to support the suppression of fires and mitigation of other hazardous situations on a Class I highway, may not exceed 86,000 pounds gross weight, or any of the following weight allowances:

(i) 24,000 pounds on a single steering axle;

(ii) 33,500 pounds on a single drive axle;

(iii) 62,000 pounds on a tandem axle; or

(iv) 52,000 pounds on a tandem rear drive steer axle.

(16) A bus, motor coach, or recreational vehicle may carry a total weight of 24,000 pounds on a single axle, but may not exceed other weight provisions of this Section.

Gross weight limits shall not apply to the combination of the tow truck and vehicles being towed. The tow truck license plate must cover the operating empty weight of the tow truck only. The weight of each vehicle being towed shall be covered by a valid license plate issued to the owner or operator of the vehicle being towed and displayed on that vehicle. If no valid plate issued to the owner or operator of that vehicle is displayed on that vehicle, or the plate displayed on that vehicle does not cover the weight of the vehicle, the weight of the vehicle shall be covered by the third tow truck plate issued to the owner or operator of the tow truck and temporarily affixed to the vehicle being towed. If a roll-back carrier is registered and being used as a tow truck, however, the license plate or plates for the tow truck must cover the gross vehicle weight, including any load carried on the bed of the roll-back carrier.

The Department may by rule or regulation prescribe additional requirements. However, nothing in this Code shall prohibit a tow truck under instructions of a police officer from legally clearing a disabled vehicle, that may be in violation of weight limitations of this Chapter, from the roadway to the berm or shoulder of the highway. If in the opinion of the police officer that location is unsafe, the officer is authorized to have the disabled vehicle towed to the nearest place of safety.

For the purpose of this subsection, gross vehicle weight rating, or GVWR, means the value specified by the manufacturer as the loaded weight of the tow truck.

(b) As used in this Section, "recycling haul" or "recycling operation" means the hauling of non-hazardous, non-special, non-putrescible materials, such as paper, glass, cans, or plastic, for subsequent use in the secondary materials market.

(c) No vehicle or combination of vehicles equipped with pneumatic tires shall be operated, unladen or with load, upon the highways of this State in violation of the provisions of any permit issued under the provisions of Sections 15-301 through 15-318 of this Chapter.

(d) No vehicle or combination of vehicles equipped with other than pneumatic tires may be operated, unladen or with load, upon the highways of this State when the gross weight on the road surface through any wheel exceeds 800 pounds per inch width of tire tread or when the gross weight on the road surface through any axle exceeds 16,000 pounds.

(e) No person shall operate a vehicle or combination of vehicles over a bridge or other elevated structure constituting part of a highway with a gross weight that is greater than the maximum weight permitted by the Department, when the structure is sign posted as provided in this Section.

(f) The Department upon request from any local authority shall, or upon its own initiative may, conduct an investigation of any bridge or other elevated structure constituting a part of a highway, and if it finds that the structure cannot with safety to itself withstand the weight of vehicles otherwise permissible under this Code the Department shall determine and declare the maximum weight of vehicles that the structures can withstand, and shall cause or permit suitable signs stating maximum weight to be erected and maintained before each end of the structure. No person shall operate a vehicle or combination of vehicles over any structure with a gross weight that is greater than the posted maximum weight.

(g) Upon the trial of any person charged with a violation of subsection (e) or (f) of this Section, proof of the determination of the maximum allowable weight by the Department and the existence of the signs, constitutes conclusive evidence of the maximum weight that can be maintained with safety to the bridge or structure.

(Source: P.A. 102-124, eff. 7-23-21.)

(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.)