Tennessee Semitrailer Length Limit

Tennessee is grandfathered at 50'0". Every state must allow 48 feet on the National Network; Tennessee kept the right to allow 50'0" and cannot drop below it.

Appendix B length50'0"

Federal floor48'0" (all states)

Kingpin conditionNone

Tractor + 2 unitsNot allowed

Tractor + 3 unitsNot allowed

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 The rule

What Tennessee has to allow

Tennessee kept 50'0" under the STAA grandfather, so anything up to that length is federally protected on the National Network and Tennessee cannot legislate below it. A standard 53-foot van is longer than that, so it runs on Tennessee state law rather than on this federal protection.

The number comes from 23 CFR Part 658 Appendix B, the STAA grandfather list. It binds Tennessee on the National Network and cannot be lowered. It says nothing about what Tennessee allows beyond it, which is where state law takes over.

02 The details

Length, kingpin and combinations

Appendix B semitrailer length: 50'0"
Kingpin-to-rear-axle condition: None in Appendix B for this state.
Tractor plus two trailing units: not allowed
Tractor plus three trailing units: not allowed
Other grandfathered combinations: not allowed
Past the legal length: a Tennessee oversize permit — see Tennessee oversize permits.

Tennessee Trailer Length FAQ

What is the legal trailer length in Tennessee without a permit?

The federally protected length on the National Network is 50'0" (23 CFR 658 Appendix B). Tennessee was grandfathered above the 48-foot floor and must keep allowing it.

Can I run a 53-foot trailer in Tennessee?

Appendix B only protects 50'0" in Tennessee. 53-foot trailers are common there under Tennessee state law, but that permission is state statute, not this federal table — confirm the current Tennessee limit and any route restriction.

Are doubles or triples allowed in Tennessee?

Tennessee has no grandfathered LCV rights in Appendix C. Standard STAA doubles only — no long doubles, no triples.

Does this length apply on every road in Tennessee?

No. Appendix B binds the National Network — the Interstates plus the designated primary routes. Off the network, and inside cities, Tennessee can and does restrict length, and posted route restrictions still apply. Check the route as well as the number.

Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: eCFR, 23 CFR 658 Appendix B and C (title 23 as of 2026-07-23). See our Terms & Disclaimer.

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Tennessee Semitrailer Length Limit

What Tennessee has to allow

Length, kingpin and combinations

Tennessee Trailer Length FAQ

More for Tennessee

Tennessee Weight Limits

Tennessee Oversize Permits

Tennessee 511

All States

Check Tennessee before you roll