Bulk carrier and tanker trucks are subject to both federal and state regulations, just like every other vehicle operated on the U.S. national road network. Larger tanks may allow the operator to haul more cargo per trip, but the roads in the U.S. are designed for vehicles of certain dimensions. A vehicle that is too large or heavy can't navigate safely on the roads and may actually damage the roads.
There is no federal limit on the total length of a tractor-trailer combination. New trailers, either cargo trailers or tanker trailers, may be up to 48 feet long. If a longer trailer was being used before December 1, 1982, it is grandfathered under the length laws in effect at the time it was originally put into service. These length limitations vary between the states.
Straight truck length is not regulated at the federal level, but it is at the state level.
In 49 states, the maximum width of the tractor and the tank is 102 inches. In Hawaii, the maximum width is 108 inches. Mirrors, handholds and safety equipment are excluded from these measurements.
The maximum total vehicle weight allowed on the national highway system is 80,000 pounds. No more than 20,000 pounds can be on each single axle and no more than 34,000 pounds can be over each tandem axle pair. Local roads may have lower weight limits.
There is no federal limit on the maximum height of a truck or trailer. The states have limits that range from 13.6 feet to 14.6 feet.