Arizona Axle Weight Limits

Maximum Legal Weight Allowed

Allowable weight shall be determined using the listed limits or the manufacturer’s weight rating, whichever is less.

Maximum Permit Weight Allowed

The Department shall require a special permit applicant to obtain an engineering analysis for transport of an overweight vehicle or vehicle and load combination exceeding 250,000 pounds.

The axle group weights shown on the previous tables are maximum weights allowed on any combination of axles within the distance between the front and rear axle of a given group to a maximum of 18 feet. The values in Table 3.01 line “A” are an expansion of the formula

W = 1.5 x 700 (L + 40),

where L is the distance between the centers of the front and rear axles of a group. The values in line “B” and in the remaining tables are computed by applying the percentages provided in the Table footnotes and are intended to increase the allowable weights based on wider axles and increased number of tires. Measured axle widths shall be rounded down to the nearest 3” increment when determining the appropriate table to use.

(Axle 1) limited to 28,000 lbs for single alone
(Axle 2 + 3); L = 4’; W = 46,200 lbs for tandem alone
(Axle 1) + (Axle 2 + 3); L = 14’; W = 56,700 lbs for the group
(Axle 4 + 5); L = 6’; W = 60,375 lbs (25% increase for 10’ wide - 8 tires)
(Axle 2 + 3 + 4); L = 16’; W = (2/3 x 58,800) + (1/3 x 73,500) = 63,700 lbs
(Axle 3 + 4 + 5); L = 18’; W = (1/3 x 60,900) + (2/3 x 76,125) = 71,050 lbs
(Axle 3 + 4); L = 12’; W = (1/2 x 54,600) + (1/2 x 68,250) = 61,425 lbs
(Axle 6 + 7 +8); L = 10’ 8”; W = 61,180 (15% increase for 10’ wide - 4 tires)

Note: The Department shall review each possible axle group that can exist within an 18-foot distance. Axle group configurations of different widths or numbers of tires shall be prorated within the total group load in determining any allowable increase over the basic formula weight.

Source of information: https://apps.azsos.gov/public_services/Title_17/17-06.pdf
https://www.azdot.gov/motor-vehicles/enforcement/commercial-vehicle-permits/general-permit-information/single-trip-permits