Mississippi OS/OD Overview
Permit Required
Yes – all oversize or overweight loads require a permit from the Mississippi Department of Transportation (MDOT).
Legal Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 53' trailer; 99' overall (some configurations)
- Weight: 80,000 lbs GVW (with standard axle spacings)
Permitted Load Maximums (Typical Upper Limits)
- Width: Up to 20' with proper escorts
- Height: Over 15' requires route survey and utility coordination
- Length: Over 120' allowed with approval
- Weight: Over 180,000 lbs with engineering review and structure analysis
Superloads require bridge analysis and may take several business days to process.
Travel Hours
- Standard: Sunrise to Sunset only
- Weekend: No travel after noon on Saturday or any time Sunday
- Holidays: Travel prohibited on major holidays and holiday weekends
- Night travel: Rarely allowed; typically only for loads under 10' wide
Escort Requirements (General Guidelines)
| Dimension | Escort Requirement |
|---|---|
| Width > 12' | 1 Escort (rear on 4-lane, front on 2-lane) |
| Width > 14' | 2 Escorts (front and rear) |
| Height > 15' | High pole escort and route survey |
| Length > 120' | 1 or more Escorts based on configuration |
Additional Notes
- “Oversize Load” signs, red flags, and amber lights are required when specified in the permit
- Bridge and route restrictions are common on rural roads—review permit route carefully
- Permits are issued through the MDOT Automated Oversize/Overweight Permitting System
Detailed Information
PERMITS: Permits valid for three days. Must have permit prior to entering the state.
OPERATING TIME: One-half hour after sunrise to one-half hour before sunset, Monday through Saturday, no Sunday travel. In addition, 24-hour movement (including Sunday) is now allowed for loads not exceeding 12' wide, 13'6" high, 99' overall length, 150,000 pounds GVW, 4' rear overhang. However, when the load is over 10' wide, an escort is required for night travel.
RESTRICTED TRAVEL: No travel on major holidays and some holiday weekends.
LEGAL DIMENSIONS: Width: 8'6" Height: 13'6" Length: 53'0 trailer, 99' overall length Overhang: With up to 53' trailer, 3' front, 14'11" rear Weight: 80,000 Gross Single – 20,000 Tandem – 34,000 Tridem – 42,000
ROUTINE PERMIT LIMITS: Width: 16' Height: 15'6" (over 15'7" requires route survey) Length: 120' Height: 16’ (Over 16' requires route survey, utility company letters, and special approval.) Weight: Single – 12,000 Tandem – 48,000 Tridem – 57,000 (63,000 on Interstate) Quad-64,000 (72,000 on interstate
ESCORTS: Width: Over 13" – 1 escort; over 16' – 2 escorts; over 10' wide at night – 1 escort Length: Over 95' – 1 escort (2 on some routes); over 105' – 2 escorts Height: The DOT may require an escort with high pole for some routes if conditions warrant. A route survey is required when exceeding 15'7" in height. Overhang: Over 15' front or rear – 1 escort.
Miscellaneous: Overweight dozer and blade must be attached, or else hauled on separate loads if blade is detached.
SIGNS, FLAGS & LIGHTS: "Oversize Load" signs are required for all loads exceeding 12 feet wide. Flags are required on all corners of loads (mounted at a height of approximately six feet above the pavement) on loads exceeding 10 feet wide. Loads over 12' in width require flashing amber lights mounted on the rear of the load and flags on the front corners or the load. Over-length loads and overhang in excess of 4 feet must be flagged.