How many cubic feet of cargo can an average 18 wheeler hold (in the back part of the truck)

18-Wheelers are known by many different names such as rig, semitrailer, semi, trailer truck and big rig.

A standard semi-trailer with the following dimension (see below) can hold up to 4085 cu. ft. of cargo:

  • length: 53'
  • width: 8.5'
  • Interior height: 9.2'

It has a maximum allowable weight with load of 80,000 lbs.; maximum cargo weight is 48,000 lbs. (24 tons) per "truckload”.

The Federal Government has enacted size regulations for CMVs (commercial motor vehicles), found on the Federal-Aid Highway Act of 1956. It explains Federal length and width requirements for certain commercial motor vehicles and where these vehicles may operate.

This Act provided a maximum vehicle width of 96 inches (2.44 meters) on the Interstate highway system. Subsequently, the Federal-Aid Highway Act of 1976 increased the allowable width for buses to 102 inches (2.6 meters). The Surface Transportation Assistance Act (STAA) of 1982 extended the same width requirement of 102 inches to commercial trucks.

At the same time, the STAA expanded the highway network on which the Federal width provision applied from the Interstate to the National Network (NN) of highways.

To learn more, see Federal Size Regulations for Commercial Motor Vehicles.

Of interest, discover 20 Insane But True Things About 18 Wheelers.

Safety tips! Written from the perspective of a trucker, learn how to drive safely around trucks at

Updated on Friday, February 20 2015 at 11:09AM EST
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