Alabama Truck Weight Limits and Permit Sources

At-a-glance summary

Field	Value	Source	Status	Confidence
Gross	Federal Interstate gross limit is 80,000 lb; Alabama-specific limits are in the FHWA state law compilation linked here.	Official source	inferred from official source	medium
Single axle	Federal Interstate single-axle limit is 20,000 lb; Alabama-specific limits are in the FHWA state law compilation linked here.	Official source	inferred from official source	medium
Tandem axle	Federal Interstate tandem limit is 34,000 lb; Alabama-specific limits are in the FHWA state law compilation linked here.	Official source	inferred from official source	medium
Bridge formula	Federal bridge formula checks apply on Interstate routes; verify state exceptions and permit conditions before movement.	Official source Official source	inferred from official source	medium
Permit agency	Alabama Department of Transportation	Official source	confirmed	high
Seasonal / frost	No official statewide seasonal or frost weight restriction was confirmed during this review.	No confirmed official source Needs official confirmation	not found in official review	low
Fine source	Alabama judicial traffic schedule materials include overweight/overheight/overlength truck citation treatment; verify the actual citation and court instructions.	Official source	inferred from official source	medium

Field-level reference data

Regular weight limits

Gross vehicle weight limit	Federal Interstate gross limit is 80,000 lb; Alabama-specific limits are in the FHWA state law compilation linked here.	Official source	inferred from official source	medium
Single axle limit	Federal Interstate single-axle limit is 20,000 lb; Alabama-specific limits are in the FHWA state law compilation linked here.	Official source	inferred from official source	medium
Tandem axle limit	Federal Interstate tandem limit is 34,000 lb; Alabama-specific limits are in the FHWA state law compilation linked here.	Official source	inferred from official source	medium
Bridge formula applies	Federal bridge formula checks apply on Interstate routes; verify state exceptions and permit conditions before movement.	Official source Official source	inferred from official source	medium
Interstate notes	Use FHWA Interstate limits together with the state source and any permit conditions.	Official source Official source	inferred from official source	medium
Non-Interstate notes	Use the reviewed state source and local postings for non-Interstate operation.	Official source	inferred from official source	medium

Axle and loading notes

Steer axle notes	Steer axle review should include axle law, tire/equipment ratings, registration, and route postings.	Official source	inferred from official source	medium
Drive axle notes	Drive axle groups should be checked against tandem/group limits and permit terms.	Official source	inferred from official source	medium
Trailer tandem notes	Trailer tandem position changes distribution and may affect spacing-sensitive checks; re-weigh after adjustment.	Official source Official source	inferred from official source	medium
Fifth wheel notes	Fifth-wheel movement redistributes weight but does not create permit authority.	Official source	inferred from official source	medium
Bridge law notes	Check FHWA bridge formula and the state source when axle spacing is close to a limit.	Official source Official source	inferred from official source	medium

Oversize / overweight permits

Permit agency	Alabama Department of Transportation	Official source	confirmed	high
Permit office name	ALDOT Oversize/Overweight Permits	Official source	confirmed	high
Official permit URL	ALDOT oversize/overweight permit source.	Official source	confirmed	high
Online permit portal	Use ALDOT's official permit source and ALPASS links for current online filing.	Official source	inferred from official source	medium
Permit contact	Use ALDOT permit contact information on the official permit source.	Official source	inferred from official source	medium
Permit notes	Permit terms, route conditions, dates, and vehicle configuration should be checked on the official permit source before travel.	Official source	inferred from official source	medium

Seasonal and special restrictions

Frost / seasonal restriction	No official statewide seasonal or frost weight restriction was confirmed during this review.	No confirmed official source Needs official confirmation	not found in official review	low
Seasonal weight notes	Local route, bridge, or permit restrictions may still apply; no statewide seasonal weight restriction was confirmed in this review.	No confirmed official source Needs official confirmation	not found in official review	low
Official seasonal URL		No confirmed official source Needs official confirmation	not found in official review	low

Fines and enforcement

Overweight fine structure	Alabama judicial traffic schedule materials include overweight/overheight/overlength truck citation treatment; verify the actual citation and court instructions.	Official source	inferred from official source	medium
Overweight ticket notes	Use the actual citation, Rule 20 traffic schedule materials, current statute, and permit terms before estimating penalties.	Official source	inferred from official source	medium
Enforcement agency	Alabama Law Enforcement Agency Motor Carrier Safety Unit	Official source	confirmed	medium
Fine official URL	Alabama Judicial Administration Rule 20 traffic schedule source.	Official source	inferred from official source	medium
CSA / safety notes	CSA impact depends on inspection and reporting; use FMCSA SMS materials and the actual inspection record.	Official source	inferred from official source	medium

Scale notes

Public scale notes	A public scale ticket is a self-check record, not state permit authority.	Official source	inferred from official source	medium
Weigh station / enforcement notes	ALEA Motor Carrier Safety Unit is the reviewed official enforcement source. Round 6 did not find a fine schedule source clear enough to raise Alabama fine confidence.	Official source	inferred from official source	medium
CAT Scale disclaimer	CAT Scale tickets are private self-check records and do not replace official permits or enforcement decisions.	Official source	inferred from official source	medium
Scale ticket notes	Use steer, drive, trailer, and gross readings to compare against official limits before travel.	Official source	inferred from official source	medium

Alabama is included with a conservative source posture: permit authority is tied to ALDOT, while regular-weight fields use FHWA’s official state-law compilation pending a deeper Alabama statute pass.

How to verify this yourself

Open the ALDOT permit source for over-legal movement. For normal legal limits, compare the FHWA compilation with current Alabama DOT or code materials before dispatch.

FAQ

Where should I verify Alabama permit requirements?

Use the official ALDOT Oversize/Overweight Permits source linked on this page before moving over legal size or weight.

Are Alabama seasonal restrictions fully confirmed here?

No. This review did not confirm a statewide seasonal or frost source, so route and permit restrictions still need checking.

Are the weight limits shown here valid for Alabama state highways?

The values shown are the federal Interstate baseline. State-specific non-Interstate limits are in the FHWA state law compilation linked here and may differ from the baseline.