Utah Axle Weight Limits

Maximum Legal Weight Allowed

The maximum gross and axle weight limitations are as follows and may not be operated in excess of:

An overweight permit must be obtained to authorize any exception to the maximum weight limitations listed above.

A highway authority may prohibit the operation of any vehicle or impose restrictions on the weight of a vehicle upon any highway under its jurisdiction.

Exception: Passenger buses may carry 24,000 lbs. on each axle provided they do not exceed manufacturer tire load ratings. This section exempts them from the 34,000 lb. tandem and bridge limitations.

Title 23: 658.17(k) Any over the road bus, or any vehicle which is regularly and exclusively used as an intrastate public agency transit passenger bus, is excluded from the axle weight limits in paragraphs (c) through (e) of this section until Oct. 1, 2009. Any State that has enforced, in the period beginning Oct. 6, 1992, and ending Nov. 30, 2005, a single axle weight limitation of 20,000 pounds or greater but less than 24,000 pounds may not enforce a single axle weight limit on these vehicles of less than 24,000 pounds.

Federal Bridge Formula

The formula limits the weight on groups of axles in order to reduce the risk of damage to highway bridges. Allowable weight depends on the number of axles a vehicle has and the distance between those axles. However, the single-or-tandem-axle weight limits supersede the Bridge Formula limits for all axles not more than 96 inches apart.

Until 1982, Federal law set only upper limits (or ceilings) on Interstate System weight limits. A few states retained significantly lower weight limits, which eventually became barriers to long-distance truck traffic. In 1982, Federal law was amended to make Interstate Systems weights limits, including the bridge formula limits, both the maximum and the minimum weights (i.e., floors and ceilings) that states must allow on the Interstate System.

W=500[(LN/N-1) + 12N + 36],

Where:

W = the maximum weight in pounds that can be carried on a group of two or more axles to the nearest 500 pounds;
L = the distance in feet between the outer axles of any two or more consecutive axles;
N = the number of axles being considered.

The calculation would then go in the following order:

• Everything within the parenthesis first
  • So you would take the length and multiply it by the number of axles being measured and divide that answer by the answer of the number of axles minus So if you had a length of 36’ and Number of axles equaled 5. It would look like this. (36 X 5 / 5-1) then you reduce it to (180 divided by 4) and this would equal 45.
  • Multiple 12 by the number of axles (5), we would get 60.
• So our formula now looks like this: W = 500[45 + 60 + 36]
• We would add all the additions on the inside of the bracket like this: W = 500[141]
• Now we multiply 141 by 500 and this gives us: W = 70,500 lbs.

Maximum Permit Weight Allowed

Single, Semi Annual, Annual Trip Permits for Overweight Non-Divisible Loads

Vehicles with a gross vehicle weight of less than 125,000 may be permitted on a single trip, semiannual, or annual basis as described below:

Overweight Non-Divisible Load Exceeding 125,000 lbs.

• Loads exceeding 125,000 pounds gross, or axle weights in R909-2-24, may only purchase single trip permits.
• Axle, bridge, and gross weight allowances will be determined based on the non-divisible bridge table formula ~1.47 x 500 (LN/N-1 + 12N + 36) or in accordance with the bridge table.
• 9 feet wide axles are allowed 7.5% more weight.
• 10 feet wide axles are allowed 15% more weight than 8 feet wide axles.
• When using an axle equipped with eight tires, rather than four, add 10% to the weight authorized for an 8 foot wide axle group.
• All tires shall be in compliance with the manufacturers tire load rating as indicated on the tire side wall.
• All STE operations must have an STE profile sheet when the axle limitations specified in Table 3 or bridge table are exceeded.

Overweight Divisible Loads

An overweight divisible load permit may be issued for moving a combination of vehicles and loads exceeding the legal limits under the following conditions:

• Gross Vehicle Weight is 129,000 pounds maximum for obtaining a permit.
• The vehicle or combination of vehicles is properly registered for 78,001 to 80,000 pounds.
  
• The width of the vehicle does not exceed 8 feet 6 inches wide or 14 feet high.
• Configurations equipped with tires 11 inches wide or less will be allowed 450 pounds per inch of tire width.
• Configurations equipped with tires 11 inches wide or greater will be allowed 500 pounds per inch of tire width.
• All axles weighing more than 10,000 pounds are required to have at least four tires per axle.
• A tridem axle group that is designed for equalized weight distribution, equipped with single tires less than 14 inches in width, will be allowed 30,000 pds.
• A tandem axle group that is designed for equalized weight distribution, equipped with single tires less than 14 inches in width, will be allowed 20,000 pds. All axles in a group must be duals or super singles to be allowed maximum weight.
• Dual or super single tires, that are 14 inches or greater, are required on all trailer axles.
• This does not apply to steering axles, self-steering variable load steering (VLS)/retractable axles, or wide base single tires (14 inch or greater as indicated by the manufacturer's sidewall rating).
• The following options are available for all axles in a group:
  • Dual tires on all axles
  • Super wide single tires (14 inches wide or greater)
  • Not to exceed 10,000 pounds per axle
  • The axle, groups of axles, and GVW do not exceed the Utah Bridge Table.
  • The combination unit will conform to the Utah Bridge Table B Extended and the legal axle and gross vehicle weight limits.

An overweight divisible load permit may be issued for moving a combination of vehicles and loads exceeding the legal limits under the following conditions:

• The vehicle or combination of vehicles is properly registered for 78,001 to 80,000 pounds;
• The width of the vehicle does not exceed 8 feet 6 inches wide or 14 feet high;
• All axles weighing more than 10,000 pounds are required to have at least four tires per axle except for steering axles, self-steering variable load suspension or retractable axles, or wide base single tires, that are 14 inches or greater as indicated by the manufacturer’s sidewall rating.

Overweight divisible load options are:

• dual tires on all axles;
• super wide single tires that are 14 inches wide or greater;
• not to exceed 10,000 pounds per axle;
• the axle, groups of axles, and GVW does not exceed the bridge formula W = 500{LN/(N-1) + 12N+36}; and
• all axles in the group must be duals or super singles to be allowed maximum authorized weight.

The combination unit will conform to the bridge formula and the legal axle and gross vehicle weight limits. A divisible load permit may not be used to transport a non-divisible load.

Exception

An overweight non-divisible load may operate with a divisible overweight permit provided the axle, gross and bridge limitations do not exceed those specified on the permit.

Source of information: https://www.udot.utah.gov/main/f?p=100:80:0:::1:T,V:4205