History Back     LEGAL LIMITATIONS AND DEPARTMENT REGULATIONS Legal Limitations Weight WEIGHTS The maximum legal axle weights on Interstate highways are: SINGLE AXLES 20,000 POUNDS TANDEM AXLES 34,000 POUNDS TRIDUM AXLES 42,000 POUNDS QUADRUM AXLES 50,000 POUNDS Axle variance of 2,000 pounds for single axles and 3,000 pounds for tandem, tridum and quadrum axles are allowed on non-Interstate highways. Therefore, the maximum legal weights on non-Interstate highways are: SINGLE AXLES 22,000 POUNDS TANDEM AXLES 37,000 POUNDS TRIDUM AXLES 45,000 POUNDS QUADRUM AXLES 53,000 POUNDS Exception: Weight limits for vehicles with tandem axles carrying forest products in their natural state shall be 40,000 pounds. The maximum legal weight on a tire is: 650 POUNDS PER INCH WIDTH OF TIRE The sum of the legal axle weights on a vehicle or combination of vehicles is its legal gross weight. However, regardless of the number and type of axles, the maximum legal gross weight of any vehicle or combination of vehicles (except a combination with a tridum or quadrum axle) is: 80,000 POUNDS Regardless of the number and type of axles, the maximum legal gross weight of any combination of vehicles which has a tridum or quadrum axle is: 83,400 POUNDS………..……...…INTERSTATE HIGHWAYS 88,000 POUNDS……………NON-INTERSTATE HIGHWAYS Vehicles may not exceed their licensed gross weight. Maximum licensed gross weight is equal to the maximum legal gross weight.