Alabama OS/OD Overview
Permit Required
Yes – all oversize and overweight loads require a permit from the Alabama DOT (ALDOT).
Size Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 57'6" (single trailer); 65' (combo)
- Weight: 80,000 lbs (GVW)
Permit Limits (Typical Maximums)
- Width: Up to 16'
- Height: Up to 16'
- Length: Up to 150'
- Weight: Up to 250,000 lbs (restrictions apply)
Loads over these limits may require special analysis, surveys, and/or escorts.
Travel Hours
- Allowed: Sunrise to Sunset
- Restricted: No Sundays or major holidays
- Night Travel: Not allowed unless under 12' wide and specifically approved
- Curfews: May apply in cities like Birmingham
Escort Requirements (General Guidelines)
| Dimension | Escort Requirement |
|---|---|
| Width > 12' | 1 Front or Rear Escort (depends on route) |
| Width > 14' | 2 Escorts (Front and Rear) |
| Length > 85' | 1 Rear Escort |
| Length > 105' | 2 Escorts (Front and Rear) |
| Height > 15' | May require pole car and route survey |
Additional Notes
- Route surveys may be needed for heights over 15’
- Must follow ALDOT-designated routes
- Mobile homes have different rules (lights, signs, etc.)
- Flags, signs, and amber lights are often required
Detailed Information
PERMITS: Permits valid for five consecutive days. Must have permit prior to entering state.
OPERATING TIME: Daylight only (one-half hour before sunrise to one-half hour after sunset) Monday through
Saturday. No travel on Sundays. Continuous travel is not allowed even when overweight only.
RESTRICTED TRAVEL: No travel on major holidays and Holiday weekends.
LEGAL DIMENSIONS:
Width: 8'6" (8' on lanes less than 12' wide) Height: 13’6”
Length: 57' trailers (53'6" on roads less than 12' wide) and 85' overall (unless trailer exceeds 57')
Overhang: 10' front, 5' rear Note: 60' Structural steel is exempt from permits and escorts
Weight: 80,000 Gross Single – 20,000 Tandem – 34,000 Tridem – 42,000
ROUTINE PERMIT LIMITS:
Width: 16' (over 16' cannot use Interstate) Height: 16’
Length: 150' (maximum overhang 20')
Overhang: 20' rear overhang is the maximum permitted.
Weight: 5 axles – 102,000 6 axles – 124,000 7 axles 146,000 Steer – 14,000 maximum without special permission Single – 22,000 Tridem – 66,000 Quad—88,000
Loads exceeding these dimensions, over 180,000 lbs. are Super Loads.
8 axles 168,000
Tandem – 44,000
ESCORTS:
Width: over 12' – 2 escorts. Height: over 16’* – 1 escort *(may be needed at lower heights on some routes)
Bucket or Blade Rule: If bucket or blade protrudes past sides of trailer at 12’ wide – 1 escort. (No escort needed if outriggers are used to prevent bucket or blade from protruding sides of trailer).
Length: With legal trailer length, over 85' – 1 escort, over 105' – 2 escorts.
Trailer length over 57’—1 rear
Overhang: over 5' rear overhang – 1 escort.
Miscellaneous: Bulldozers, front end loaders and similar equipment shall be loaded with the blade to the rear any time the blade protrudes beyond the transporting vehicle. Overweight dozer and blade must be attached, or else hauled on separate loads if blade is detached. 60' Structural steel is exempt from permits and escorts.
SIGNS, FLAGS & LIGHTS:
“Oversize Load” signs front and rear of any overwidth or overlength vehicle. Flags must be placed at front and rear corners of any overdimensional load or vehicle. Over 4' rear overhang requires lights at night. (Over 5' needs permit, and can't run at night). There are no sign or flag requirements for overheight only or overweight only loads.