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: over 17' makes the load a Super Load. (An earlier version of this page said “up to 20' with proper escorts” — the only 20-foot figure in the manual is a minimum pavement width for pole-hauling blanket permits, not a maximum load width.)
- Height: over 15'7" makes the load a Super Load and requires a height pole
- Length: over 121' makes the load a Super Load. The escort trigger is much lower — over 99'
- Weight: 189,999 lbs or greater makes the load a Super Load; two blue-light escorts are required at 300,000 lbs or more
Superloads require bridge analysis and may take several business days to process.
Travel Hours
- Daylight Hours (defined two ways): loads 12' wide or less, sunrise to sunset per the National Weather Service; loads over 12' wide, 30 minutes after sunrise to 30 minutes before sunset
- Night travel: permitted for loads not exceeding 12' wide, 150,000 lb, 99' long or 13'6" high (maximum height is route-dependent), with rear overhang no more than 4'. Escorts are required at 10' wide and over — see the table below
- Holidays: no movement after 12:00 noon on days preceding or on New Year's Day, Memorial Day, Fourth of July, Labor Day, Thanksgiving Day and Christmas, unless otherwise permitted
- Inclement weather: overwidth loads shall not be moved during inclement weather
- Sunday: the 2026 manual states no general Sunday restriction. A Monday–Saturday limit does exist, but only under a Special Heavy Equipment Blanket Permit and only for loads over 12' and up to 14' wide; under that same permit loads at or under 12' wide get 24-hour, 7-day movement
Escort Requirements (General Guidelines)
| Dimension | Escort Requirement |
|---|---|
| Width 10' or greater — at night | 1 front escort on a two-lane roadway; 1 rear escort on a divided highway. Plus flashing amber lights on the rear of the load. Under 10' wide at night: amber lights only, no escort |
| Width 13' or greater — daylight | 1 front escort on a two-lane roadway; 1 rear escort on a divided highway. Plus flashing amber lights on the rear of the load |
| Width 18' and over | A police escort (“blue lights”) may be required, depending on route and load conditions, at the discretion of the Executive Director or the Commission — discretionary, not automatic |
| Length exceeding 99' | Permit and a front and/or rear escort |
| Rear overhang 15' or greater | Permit and a front and/or rear escort |
| Front projection 15' or greater | Front and/or rear escort (projection over 3' already requires a permit) |
| Height over 13'6" up to 15'7" | No fixed trigger published. A permit is required above 13'6", and MDOT's General Safety Requirements let the permit impose “escorts with a height pole” when necessary for the protection of the public or the highway, naming no height. Route-dependent — settle it on the permit face |
| Height 15'7" or more | Height pole required (superload) — the manual's only numeric pole trigger |
| Height 15'9" or more | Two blue-light escorts plus a height pole escort. Exceptions at the discretion of the MDOT Permit Division Director, based on route |
| Length 160' or more | Two blue-light escorts, one front and one rear |
| Weight 300,000 lb or more | Two blue-light escorts. Exceptions at the Director's discretion, based on route |
| Crossing bridges | Escorts may be required on a permitted route |
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
Source: MDOT Permit & Motor Carrier Division Manual, 2026 edition (1/13/2026), read in full. Informational only — always verify against the live permit office before any move; permit conditions control.
Detailed Information
PERMITS: Permits valid for three days. Must have permit prior to entering the state.
OPERATING TIME: MDOT defines Daylight Hours two ways: for loads 12' wide or less, sunrise to sunset as reported by the National Weather Service; for loads greater than 12' wide, one-half hour after sunrise to one-half hour before sunset. Night movement is permitted for loads not exceeding 12' wide, 150,000 lb, 99' long or 13'6" high (maximum height is route-dependent), with rear overhang no more than 4'. At night, a load 10' wide or greater requires a front escort on a two-lane roadway or a rear escort on a divided highway, in both cases with flashing amber lights on the rear of the load; under 10' wide needs the amber lights only. The 2026 manual states no general Sunday restriction — a Monday–Saturday limit exists only under a Special Heavy Equipment Blanket Permit, and only for loads over 12' and up to 14' wide.
RESTRICTED TRAVEL: No movement after 12:00 noon on days preceding or on New Year's Day, Memorial Day, Fourth of July, Labor Day, Thanksgiving Day and Christmas, unless otherwise permitted. Overwidth loads shall not be moved during inclement weather.
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
PERMIT ENVELOPES: MDOT does not publish a single table of “routine” maximums, so the meaningful ceilings are the permit classes themselves. The Oversize Blanket Permit covers loads not exceeding 14' wide, 14' high and 120' long, with no more than 14'11" rear overhang, and the load must be one continuous piece ($100 per year, per company) — this is where the 120-foot figure comes from, and it is a permit ceiling, not an escort trigger. Above the Super Load thresholds — over 17' wide, over 121' long, over 15'7" high, or 189,999 lbs or greater — the move goes to a Super Load Permit and the escort conditions are written on the permit face. A Single Trip Permit covers a specific vehicle or load for up to three consecutive days.
ESCORTS: See the table above — it is the corrected version, read from MDOT's 2026 manual. An earlier version of this paragraph carried four errors worth naming, because they circulate widely on other sites: it wrote the width trigger as 13 inches rather than 13 feet; it claimed a two-escort tier at 16', which does not exist in the manual; it gave length tiers of 95' and 105', when the manual's only length escort provision is over 99', front and/or rear; and it treated the height pole as purely discretionary, when 15'7" is a firm trigger. What it got right: a pole can be required below that at MDOT's discretion, and overhang over 15' front or rear does call for an 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.
