Federal Regulations
Part 658: Truck Weight &
Size
| This section deals with the provisions of the Surface Transportation
Assistance Act and the national policies that govern truck and bus size and weight
according to the 49 Code of Federal Regulations (CFR.) Read more at
the FMCSA website:
http://www.fmcsa.dot.gov/rulesregs/fmcsrhome.htm |
The Federal Government began to regulate the size of commercial motor vehicles with the Federal-Aid Highway Act of 1956, when it established a maximum vehicle width of 96 inches on Interstate Highways. Twenty years later, in 1976, the width for buses was increased to 102 inches. It wasn't until 1982 that width limitations were extended to 102 inches for all commercial vehicles. At that time, length limitations were also enacted for the National Network of highways. There are no Federal height limitations, so States set their own, mostly ranging from 13'6" to 14', with exceptions made for lower clearances on particular roads. |
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The Federal law mandates that each State allow a maximum gross weight of 80,000 pounds (40 tons) (sec.133). |
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The maximum width limit for commercial
vehicles on the National Network of highways has been established as 102 inches, except in
Hawaii, where it is 108 inches. To standardize the width on an international basis,
it is considered that the 102-inch width will translate to its approximate metric
equivalent of 2.6 meters or 102.36 inches. This width limit does not apply to all
vehicles. Individual States issue permits to allow over-width vehicles to travel on
highways. |
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Federal length limits are basically the minimum the States must allow for semi trailers on highways and reasonable access routes. The minimum allowable length for single trailers is 48 feet, for doubles, 28 feet each, or the "grandfathered" limit for a particular State (sec.411). The maximum allowed length for single trailers is 53 feet (57 feet in some States). |
Grandfathered Length Limits
Applies to semi trailers that were actually and lawfully operating in a
truck tractor-semi trailer combination in a State on December 1, 1982.
| State | Feet & Inches | Meters |
| Alabama | 53'6" | 16.31 |
| Alaska | 48'0" | 14.63 |
| Arizona | 57'6" | 17.53 |
| Arkansas | 53'6" | 16.31 |
| California | 48'0" | 14.63 |
| Colorado | 57'4 | 17.48 |
| Connecticut | 48'0" | 14.63 |
| Delaware | 53'0" | 16.15 |
| District of Columbia | 48'0" | 14.63 |
| Florida | 48'0" | 14.63 |
| Georgia | 48'0" | 14.63 |
| Hawaii | 48'0" | 14.63 |
| Idaho | 48'0" | 14.63 |
| Illinois | 53'0" | 16.15 |
| Indiana | 48'6" | 14.78 |
| Iowa | 53'0" | 16.15 |
| Kansas | 57'6" | 17.53 |
| Kentucky | 53'0" | 16.15 |
| Louisiana | 59'6" | 18.14 |
| Maine | 48'0" | 14.63 |
| Maryland | 48'0" | 14.63 |
| Massachusetts | 48'0" | 14.63 |
| Michigan | 48'0" | 14.63 |
| Minnesota | 48'0" | 14.63 |
| Mississippi | 53'0" | 16.15 |
| Missouri | 53'0" | 16.15 |
| Montana | 53'0" | 16.15 |
| Nebraska | 53'0" | 16.15 |
| Nevada | 53'0" | 16.15 |
| New Hampshire | 48'0" | 14.63 |
| New Jersey | 48'0" | 14.63 |
| New Mexico | 57'6" | 17.53 |
| New York | 48'0" | 14.63 |
| North Carolina | 48'0" | 14.63 |
| North Dakota | 53'0" | 16.15 |
| Ohio | 53'0" | 16.15 |
| Oklahoma | 59'6" | 18.14 |
| Oregon | 53'0" | 16.15 |
| Pennsylvania | 53'0" | 16.15 |
| Puerto Rico | 48'0" | 14.63 |
| Rhode Island | 48'6" | 14.78 |
| South Carolina | 48'0" | 14.63 |
| South Dakota | 53'0" | 16.15 |
| Tennessee | 50'0" | 15.24 |
| Texas | 59'0" | 17.98 |
| Utah | 48'0" | 14.63 |
| Vermont | 48'0" | 14.63 |
| Virginia | 48'0" | 14.63 |
| Washington | 48'0" | 14.63 |
| West Virginia | 48'0" | 14.63 |
| Wisconsin | 48'0" | 14.63 |
| Wyoming | 57'4" | 17.48 |
Within Our Borders & Beyond
| U.S. | Canada | Mexico | |
| Single Axle | 20,000 lbs. | N/A | N/A |
| Steering Axle | Bridge Formula B* | 12,125 lbs. | 14,330 lbs. |
| Tandem Axle | 34,000 lbs. | 37,479 lbs. | 42,990 lbs. |
| Tridem Axle | Bridge Formula B* | 46,297-52,911 lbs. | 49,604 |
| Gross Vehicle Weight | 80,000 lbs. | 137,500 lbs. | 136,600 lbs. |
| Width | 102-inches | unknown | unknown |
| Semi-Trailer Length | 48-feet (min.) | 53-feet (max.) | 68.2-feet (max.) |
| Twin-Trailer Length | 28-feet (per trailer) | unknown | 102.7-feet (overall) |
| Overall Vehicle Length | 75.5-feet (max.) | unknown |
|
Bridge Gross Weight Formula
B: W=500[(LN/N-1)+12N+36] |
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If
you must err...
!Err on the
side of Caution!
 |
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Rights Reserved.
Last revised:
January 28, 2004