Alabama Truck Weight Limits
Complete guide to commercial vehicle weight regulations in Alabama, including axle limits, permit requirements, and seasonal restrictions.
Weight Limits
| Axle Type | Alabama Limit | Federal Limit | Difference |
|---|---|---|---|
| Single Axle | 20,000 lbs | 20,000 lbs | 0 lbs |
| Tandem Axle | 34,000 lbs | 34,000 lbs | 0 lbs |
| Gross Vehicle Weight | 80,000 lbs | 80,000 lbs | 0 lbs |
| Steer Axle (min) | 12,000 lbs | 12,000 lbs | 0 lbs |
| Steer Axle (max) | 20,000 lbs | 20,000 lbs | 0 lbs |
Alabama has source-verified table, spacing, route, permit, or vehicle-specific rules. The calculator applies verified base limits and implemented contexts, but exact special-case output still needs source-chart fixtures.
Alabama has route-specific weight limits. Default calculation uses interstate/standard operation; select a route context for higher state-route limits.
Showing interstate route, standard operation.
Enforcement tolerance: 10% on gross weight.
Bridge Formula
Alabama uses the standard Federal Bridge Formula to calculate maximum weight on groups of consecutive axles.
- W = Maximum weight (lbs)
- L = Distance between outer axles (ft)
- N = Number of axles in the group
Permissible Gross Loads in Alabama
| Permissible Gross Loads for Vehicles in Alabama | ||||||||
|---|---|---|---|---|---|---|---|---|
| Based on FederalBridge Formula: W = 500 × [LN/(N-1) + 12N + 36] | ||||||||
| Showing interstate route, standard operation | ||||||||
Distance (ft) L | 2 AXLES | 3 AXLES | 4 AXLES | 5 AXLES | 6 AXLES | 7 AXLES | 8 AXLES | 9 AXLES |
| 4 | 34,000 | — | — | — | — | — | — | — |
| 5 | 34,000 | — | — | — | — | — | — | — |
| 6 | 34,000 | — | — | — | — | — | — | — |
| 7 | 34,000 | — | — | — | — | — | — | — |
| 8 | 34,000 | 42,000 | — | — | — | — | — | — |
| 9 | 39,000 | 42,500 | — | — | — | — | — | — |
| 10 | 40,000 | 43,500 | — | — | — | — | — | — |
| 11 | 40,000 | 44,000 | — | — | — | — | — | — |
| 12 | 40,000 | 45,000 | 50,000 | — | — | — | — | — |
| 13 | 40,000 | 45,500 | 50,500 | — | — | — | — | — |
| 14 | 40,000 | 46,500 | 51,500 | — | — | — | — | 80,000 |
| 15 | 40,000 | 47,000 | 52,000 | — | — | — | — | 80,000 |
| 16 | 40,000 | 48,000 | 52,500 | 58,000 | — | — | — | 80,000 |
| 17 | 40,000 | 48,500 | 53,500 | 58,500 | — | — | — | 80,000 |
| 18 | 40,000 | 49,500 | 54,000 | 59,000 | — | — | — | 80,000 |
| 19 | 40,000 | 50,000 | 54,500 | 60,000 | — | — | — | 80,000 |
| 20 | 40,000 | 51,000 | 55,500 | 60,500 | 66,000 | — | — | 80,000 |
| 21 | 40,000 | 51,500 | 56,000 | 61,000 | 66,500 | — | — | 80,000 |
| 22 | 40,000 | 52,500 | 56,500 | 61,500 | 67,000 | — | — | 80,000 |
| 23 | 40,000 | 53,000 | 57,500 | 62,500 | 68,000 | — | — | 80,000 |
| 24 | 40,000 | 54,000 | 58,000 | 63,000 | 68,500 | 74,000 | — | 80,000 |
| 25 | 40,000 | 54,500 | 58,500 | 63,500 | 69,000 | 74,500 | 80,000 | 80,000 |
| 26 | 40,000 | 55,500 | 59,500 | 64,000 | 69,500 | 75,000 | 80,000 | 80,000 |
| 27 | 40,000 | 56,000 | 60,000 | 65,000 | 70,000 | 75,500 | 80,000 | 80,000 |
| 28 | 40,000 | 57,000 | 60,500 | 65,500 | 71,000 | 76,500 | 80,000 | 80,000 |
| 29 | 40,000 | 57,500 | 61,500 | 66,000 | 71,500 | 77,000 | 80,000 | 80,000 |
| 30 | 40,000 | 58,500 | 62,000 | 66,500 | 72,000 | 77,500 | 80,000 | 80,000 |
| 31 | 40,000 | 59,000 | 62,500 | 67,500 | 72,500 | 78,000 | 80,000 | 80,000 |
| 32 | 40,000 | 60,000 | 63,500 | 68,000 | 73,000 | 78,500 | 80,000 | 80,000 |
| 33 | 40,000 | 60,500 | 64,000 | 68,500 | 74,000 | 79,000 | 80,000 | 80,000 |
| 34 | 40,000 | 61,500 | 64,500 | 69,000 | 74,500 | 80,000 | 80,000 | 80,000 |
| 35 | 40,000 | 62,000 | 65,500 | 70,000 | 75,000 | 80,000 | 80,000 | 80,000 |
| 36 | 40,000 | 63,000 | 66,000 | 70,500 | 75,500 | 80,000 | 80,000 | 80,000 |
| 37 | 40,000 | 63,500 | 66,500 | 71,000 | 76,000 | 80,000 | 80,000 | 80,000 |
| 38 | 40,000 | 64,500 | 67,500 | 71,500 | 77,000 | 80,000 | 80,000 | 80,000 |
| 39 | 40,000 | 65,000 | 68,000 | 72,500 | 77,500 | 80,000 | 80,000 | 80,000 |
| 40 | 40,000 | 66,000 | 68,500 | 73,000 | 78,000 | 80,000 | 80,000 | 80,000 |
| 41 | 40,000 | 66,500 | 69,500 | 73,500 | 78,500 | 80,000 | 80,000 | 80,000 |
| 42 | 40,000 | 67,500 | 70,000 | 74,000 | 79,000 | 80,000 | 80,000 | 80,000 |
| 43 | 40,000 | 68,000 | 70,500 | 75,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 44 | 40,000 | 69,000 | 71,500 | 75,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 45 | 40,000 | 69,500 | 72,000 | 76,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 46 | 40,000 | 70,500 | 72,500 | 76,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 47 | 40,000 | 71,000 | 73,500 | 77,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 48 | 40,000 | 72,000 | 74,000 | 78,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 49 | 40,000 | 72,500 | 74,500 | 78,500 | 80,000 | 80,000 | 80,000 | 80,000 |
| 50 | 40,000 | 73,500 | 75,500 | 79,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 51 | 40,000 | 74,000 | 76,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 52 | 40,000 | 75,000 | 76,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 53 | 40,000 | 75,500 | 77,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 54 | 40,000 | 76,500 | 78,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 55 | 40,000 | 77,000 | 78,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 56 | 40,000 | 78,000 | 79,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 57 | 40,000 | 78,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 58 | 40,000 | 79,500 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 59 | 40,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
| 60 | 40,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 | 80,000 |
Values reflect FHWA policy of rounding down when calculated weights fall exactly halfway between 500-pound increments.
Alabama allows a 10% enforcement tolerance on gross weight.
Alabama has source-verified table, spacing, route, permit, or vehicle-specific rules. The calculator applies verified base limits and implemented contexts, but exact special-case output still needs source-chart fixtures.
Alabama has route-specific weight limits. Default calculation uses interstate/standard operation; select a route context for higher state-route limits.
Always verify current regulations with Alabama DOT before making shipping decisions.
Permit Information
Requirements & Costs
- Overweight threshold
- 80,000 lbs
- Single trip permit
- $50
- Annual permit
- $600
- Processing time
- 24 hours
- Divisible loads
- Not permitted
- Online application
- Available
Required Documents
- Insurance
- Registration
Special Vehicle Provisions
dump Truck Exemptions
Dump trucks, dump trailers, concrete mixing trucks, and fuel oil/gasoline trucks are exempt from axle spacing (bridge formula) requirements. Limited to 20,000 lbs per axle plus scale tolerances. A tri-axle dump can carry up to 80,000 lbs under this exemption.
construction
Asphalt plant mix delivery trucks operating within 50 miles of home base are exempt from axle spacing requirements, provided they do not exceed max GVW.
idle Reduction
Additional 400 lbs allowance for idle reduction technology (effective Oct 1, 2025).
Contact Information
Permit Office
Official Website
Alabama DOT WebsiteImportant Notes
- Dump trucks, concrete mixers, and fuel trucks are EXEMPT from bridge formula (axle spacing) requirements
- Legislation (SB 110/HB 204) proposes increasing single axle to 22,000 lbs and tandem to 44,000 lbs for log trucks
- ALDOT warns 350 bridges would need weight restrictions if passed
- Call 1-800-499-2782, option 4 for permit assistance
Calculate Your Weight Compliance
Use our interactive calculator to check if your truck configuration is compliant with Alabama regulations.
Open Weight CalculatorNeighboring States
Need Help With Alabama Compliance?
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Get Expert ConsultationSource: Alabama Code Title 32 | Last Updated: 1/15/2025 | Effective: 1/1/2025
Always verify current regulations with official sources before making shipping decisions.