Regulations No. 32 23 CFR 658 App. B

Legal Semitrailer Length by State

The semitrailer length every state must allow on the National Network without a permit, from 23 CFR Part 658 Appendix B, plus the grandfathered doubles and triples rights from Appendix C. 27 jurisdictions sit above the 48-foot federal floor. Covers all 50 states and DC. Reference only, not legal advice.

48 ftFederal floor, every state
59'6"Longest (Louisiana)
27Grandfathered above 48 ft
26With LCV rights
This is a floor, not your length limit. Appendix B lists what a state was grandfathered to keep under the STAA of 1982 and must go on allowing on the National Network. It is not the state's own limit, and it is not permission to run that length on any road you like. Most states allow 53-foot semitrailers under their own law — that permission comes from state statute, not from this table — and every state can still restrict length on specific routes, in cities, and off the National Network. Use this to know the federal baseline, then check the state limit and the route.
01 How it works

One federal floor, 27 states grandfathered above it

The Surface Transportation Assistance Act of 1982 stopped states from squeezing interstate freight with short trailer limits. Since then no state may hold a semitrailer in a tractor-semitrailer combination below 48 feet on the National Network (23 CFR 658.13). States that already allowed longer trailers kept that right, and those lengths are frozen in Appendix B — from 59'6" in Louisiana down to the 48-foot floor.

Read the number as a guarantee, not a ceiling. Appendix B says what the state has to let you do. What the state actually allows on its own roads is state law, and for most of them that is 53 feet. The two answers only ever meet on the National Network.

02 The kingpin catch

Three states where the number is not the whole rule

California, Indiana, Wisconsin appear at the 48-foot floor. A 53-foot trailer is still legal in all three without a permit — but only if the kingpin sits close enough to the rear axle.

This is the detail that catches people. In California a standard 53-foot van with a long kingpin setting is not a long load needing a permit, it is an illegal one. Measure before you plan the run.

03 By state

Semitrailer length and LCV rights for all 50 states and DC

Tap a state for the full Appendix B and Appendix C entry, the kingpin condition where one applies, and what it means for a standard 53-foot trailer.

StateAppendix B lengthStatusTractor + 2 unitsTractor + 3 units
Alabama AL 53'6" Grandfathered longer Not allowed Not allowed
Alaska AK 48'0" Federal floor 95' 110'
Arizona AZ 57'6" Grandfathered longer 95' 129K 95' 129K
Arkansas AR 53'6" Grandfathered longer Not allowed Not allowed
California CA 48'0" 53 ft on a kingpin limit KPRA 38 ft Not allowed Not allowed
Colorado CO 57'4" Grandfathered longer 111' 110K 115.5' 110K
Connecticut CT 48'0" Federal floor Not allowed Not allowed
Delaware DE 53'0" Grandfathered longer Not allowed Not allowed
District of Columbia DC 48'0" Federal floor Not allowed Not allowed
Florida FL 48'0" Federal floor 106' (2) Not allowed
Georgia GA 48'0" Federal floor Not allowed Not allowed
Hawaii HI 48'0" Federal floor 65' (2) Not allowed
Idaho ID 48'0" Federal floor 95' 105.5K 95' 105.5K
Illinois IL 53'0" Grandfathered longer Not allowed Not allowed
Indiana IN 48'6" 53 ft on a kingpin limit KPRA 40'6" 106' 127.4K 104.5' 127.4K
Iowa IA 53'0" Grandfathered longer 100' 129K 100' 129K
Kansas KS 57'6" Grandfathered longer 109' 120K 109' 120K
Kentucky KY 53'0" Grandfathered longer Not allowed Not allowed
Louisiana LA 59'6" Grandfathered longer Not allowed Not allowed
Maine ME 48'0" Federal floor Not allowed Not allowed
Maryland MD 48'0" Federal floor Not allowed Not allowed
Massachusetts MA 48'0" Federal floor 104' 127.4K Not allowed
Michigan MI 48'0" Federal floor 58' 164K Not allowed
Minnesota MN 48'0" Federal floor Not allowed Not allowed
Mississippi MS 53'0" Grandfathered longer 65' (2) Not allowed
Missouri MO 53'0" Grandfathered longer 110' 120K(4) 109' 120K
Montana MT 53'0" Grandfathered longer 93' 137.8K 100' 131.06K
Nebraska NE 53'0" Grandfathered longer 95' 95K 95' (2)
Nevada NV 53'0" Grandfathered longer 95' 129K 95' 129K
New Hampshire NH 48'0" Federal floor Not allowed Not allowed
New Jersey NJ 48'0" Federal floor Not allowed Not allowed
New Mexico NM 57'6" Grandfathered longer 86.4K(3) Not allowed
New York NY 48'0" Federal floor 102' 143K Not allowed
North Carolina NC 48'0" Federal floor Not allowed Not allowed
North Dakota ND 53'0" Grandfathered longer 103' 105.5K 100' 105.5K
Ohio OH 53'0" Grandfathered longer 102' 127.4K 95' 115K
Oklahoma OK 59'6" Grandfathered longer 110' 90K 95' 90K
Oregon OR 53'0" Grandfathered longer 68' 105.5K 96' 105.5K
Pennsylvania PA 53'0" Grandfathered longer Not allowed Not allowed
Rhode Island RI 48'6" Grandfathered longer Not allowed Not allowed
South Carolina SC 48'0" Federal floor Not allowed Not allowed
South Dakota SD 53'0" Grandfathered longer 100' 129K 100' 129K
Tennessee TN 50'0" Grandfathered longer Not allowed Not allowed
Texas TX 59'0" Grandfathered longer Not allowed Not allowed
Utah UT 48'0" Federal floor 95' 129K 95' 129K
Vermont VT 48'0" Federal floor Not allowed Not allowed
Virginia VA 48'0" Federal floor Not allowed Not allowed
Washington WA 48'0" Federal floor 68' 105.5K Not allowed
West Virginia WV 48'0" Federal floor Not allowed Not allowed
Wisconsin WI 48'0" 53 ft on a kingpin limit KPRA 41 ft Not allowed Not allowed
Wyoming WY 57'4" Grandfathered longer 81' 117K Not allowed

Source: eCFR, 23 CFR Part 658 Appendix B (last amended 2007-02-20) and Appendix C (last amended 2019-08-22), title 23 as published 2026-07-23. Puerto Rico is also listed in both appendices at 48'0" with no LCV rights. Reference information, not legal advice.

Trailer Length FAQ

What is the legal semitrailer length without a permit?
Federal law makes every state allow at least 48 feet on the National Network (23 CFR 658.13). 27 jurisdictions were grandfathered higher under the STAA of 1982 and are listed in 23 CFR 658 Appendix B, up to 59'6" in Louisiana. Above that number you are into a state oversize permit.
Why does the table say 48 feet when everyone runs 53?
Because Appendix B is a federal floor, not a state's limit. It says what a state must allow, and most states independently allow 53-foot semitrailers under their own statute — which is why 53 feet became the industry standard. The table tells you the federally protected baseline. Your state limit comes from state law.
Which states put a kingpin condition on a 53-foot trailer?
California, Indiana, Wisconsin. Each is listed at the 48-foot floor in the table, and each allows 53 feet without a permit only if the kingpin-to-rearmost-axle distance stays inside a set figure. Get the number wrong in California and a standard 53-footer is illegal, not merely long.
Can I run doubles or triples?
26 jurisdictions hold grandfathered longer-combination-vehicle rights under 23 CFR 658 Appendix C, mostly in the west and the plains. The rest are marked not allowed, which means no LCV beyond standard STAA doubles. Each state page shows the maximum length and gross weight for its tractor plus two and plus three units.
How current is this table?
It is generated straight from the eCFR API. Appendix B was last amended 2007-02-20 and Appendix C 2019-08-22; the copy here reflects title 23 as of 2026-07-23. The federal appendices move rarely. State length statutes change more often, so confirm with the state before you rely on it.
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