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Haul Math

Louisiana Truck Weight and Size Limits

Legal limits for a truck in Louisiana without a permit: Interstate axle and gross weights, height, width, and semitrailer length, each with its official source.

Data pending verification

Some official figures this page relies on haven't been confirmed against the source yet. Don't rely on results here until this notice is gone.

What's pending
  • weight-limits/states/louisiana

Louisiana limits at a glance

Louisiana truck size and weight limits with sources
LimitLouisianaSource
Interstate gross weight80,000 lb23 CFR 658.17, Weight (eCFR)
Interstate single axle20,000 lb23 CFR 658.17, Weight (eCFR)
Interstate tandem axle34,000 lb23 CFR 658.17, Weight (eCFR)
Width (National Network)102 in23 CFR 658.15, Width (eCFR)
HeightPending verificationFHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix A: Louisiana
Semitrailer lengthPending verificationFHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix A: Louisiana
Grandfathered semitrailer length59 ft 6 in23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR)

Interstate weight limits

Federal law sets the Interstate limits at 20,000 lb on a single axle, 34,000 lb on a tandem, and 80,000 lb gross, with the bridge formula on every axle group (23 CFR 658.17). States may keep higher limits they had before the federal limits took effect ("grandfather rights").

FHWA on Louisiana: Sugarcane: The Secretary issues annual special permits to persons who operate trucks that haul sugarcane. These permits allow up to 100,000 lbs. gross vehicle weight on any State-maintained highway, including Interstate highways, for up to 100 days. Beginning August 1, 2012, the Secretary may not issue an annual special permit to any owner or operator of a vehicle hauling sugarcane who has not added an additional single axle with dual mounted tires on the sugarcane trailer for a total of six axles for the vehicle and trailer combination. (La. Rev. Stat. Ann. §32-387.7)

Bridge formula check with Louisiana limits

A 5-axle tractor-trailer is filled in. Change the spacings and weights to match your rig; the limits for single axles, tandems, and gross are Louisiana's Interstate limits.

Axle spacings

Center of one axle to the center of the next, in feet. Axle 1 is the steer axle. 4 ft 6 in = 4.5.

Axle weights (optional)

From your scale ticket. Leave all blank to see the limits only.

Your result

Enter your axle spacings and tap "Check bridge formula". A 5-axle tractor-trailer is filled in.

Open the full bridge formula calculator →

Louisiana limits off the Interstate

FHWA's summary of Louisiana law for trucks in regular operation (no permit), including non-Interstate highways. It reflects state law as of October 1, 2012; check the state for later changes.

Single axle
20,000 lbs. / 18,000 lbs. on high pressure or solid rubber tires
Tandem axle
34,000 lbs. / 32,000 lbs. on high pressure or solid rubber tires
Tridem axle
42,000 lbs.
Gross weight
80,000 lbs. / 83,400 lbs. for vehicle combinations with tridum or quadrum axles on Interstate highways / 88,000 lbs. for vehicle combinations with tridum or quadrum axles on non-Interstate highways
Other
Axle tolerances on non-Interstate highways: additional 2,000 lbs. for single axles and 3,000 lbs. for tandem, tridem, or quadrum axles / Quadrum axle: 50,000 lbs. / 650 lbs. per inch width of tire

Where Louisiana allows more than federal limits

Height, width, and length

Over these limits you need a permit. Louisiana oversize/overweight permits (225-343-2345 or 800-654-1433).

Louisiana compared with neighboring states

Interstate weight limits, height, and semitrailer length. "Pending" means not yet verified.
StateGrossSingleTandemHeightSemitrailer
Louisiana80,000 lb20,000 lb34,000 lbPendingPending
Arkansas80,000 lb20,000 lb34,000 lb14 ftPending
Mississippi80,000 lb20,000 lb34,000 lbPendingPending
Texas80,000 lb20,000 lb34,000 lb14 ft59 ft

Sources

Source: 23 CFR 658.17, Weight (eCFR) · Last verified Sep 28, 2026

Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix A: Louisiana · Effective Oct 1, 2012 · Last verified Sep 28, 2026

Source: 23 CFR 658.15, Width (eCFR) · Last verified Sep 28, 2026

Source: 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) · Last verified Sep 28, 2026

Source: FHWA, Oversize/Overweight Load Permits: State permit contacts · Last verified Sep 28, 2026

Limits change, and cities, counties, and posted bridges can set lower ones. Check with Louisiana before you run a load near the limits. Page data last verified Sep 28, 2026.

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