The American Driver
From Drivers...For Drivers
National Weight & Size Provisions
Width
Height
Semi-Trailer in
Tractor-Semi-Trailer Combo
Full Trailer
Doubles
Single Axle
(lb.)
Tandem Axle
(lb.)
Gross Vehicle Weight
(lb.)
102"
14'0"
53'
53'
81'6"
(
1)
20,000
(
2)
34,000
(
2)
80,000
State/Provincial Weight & Size Limits
Steering Axle
(lb.)
Single Axle
(lb.)
Tandem Axle
(lb.)
Gross Vehicle Weight
(lb.)
600 lb./inch
of tire width
20,000
(
2)
34,000
80,000
(
3)
Width
Height
Straight Truck
Semi-Trailer
Full Trailer
Tractor &
Semi-Trailer
Tractor &
Semi-Trailer &
Full Trailer
Tractor & Triples
Other/Specials
102"
14'0"
45'
53'
28'6"
Controlled by
single trailer
length
(4)
(5)
(6)
(1)  Maximum length of either trailer may not exceed 45'.
(2)  Single tired axles (other than steering tires) are limited to 500 lb./inch of tire width.
(3)  On Interstate system.  Primary highway weights governed by bridge formula and number of axles.
(4)  Overall length, excluding tractor, may not exceed 81'6".  Neither trailer may exceed 45'.
(5)  Allowed on Interstate and designated highways by permit only.
(6)  Seasonal weight limits apply;  call DOT at 605-773-3704.