Michigan Oversize & Overweight Permit Rules
What a load can be in Michigan without a permit, where the permit and escort tiers start on non-interstate and interstate, when it can move, and who to call. Every figure is the JaloPermit Atlas entry for Michigan, shown as the app shows it.
Rules as of Jul 31, 2026 · Links checked Jul 13, 2026
Read this before you trust a number. Rules change. The issued permit, posted signs and the state permit office always win over this page. JaloPermit is a reading aid, not a permit-filing service. Guests get 3 free decodes a day with no account and no card, logged-in users get 10 a day, and extra decodes are $3.50 each with no subscription.
What moves in Michigan without a permit
Legal limits are the dimensions and gross weight a vehicle may run at without an oversize or overweight permit. Michigan publishes its length limit as semitrailer, so compare it against that measurement on your permit, not the overall rig.
Where the permit and escort tiers start
| Dimension | Legal without permit | Permit tier starts | First escort on non-interstate | First escort on interstate |
|---|---|---|---|---|
| Width | 8'6" | 8'7" | 12'1" · Front escort | 12'1" · Rear escort |
| Height | 13'6" | 13'7" | 14'7" · Front + High pole | 14'7" · Front + High pole |
| Length | 53'0"semitrailer | 53'1" | 90'1" · Rear escort | 90'1" · Rear escort |
| Weight | 80,000 lbs | Check the state permit office. | — | — |
"Permit tier starts" is the lowest size in the Atlas ladder that needs a permit. "First escort" is the lowest size that adds a private or police escort on that road class; the full ladder with each tier's rule and source is below.
Michigan escort ladder, tier by tier
Open a tier to read the rule behind it, quoted with its source. Amber tiers add a police escort or a superload review; grey tiers are permit-only with conditions.
On non-interstate
Escorts begin at 12'1" wide
Width
Permit required8'7" – 12'
Permit required over legal 8'6" width; no escort provision attaches at this width. Verified on MDOT-issued permit 125148087602 (10'0" wide): no escort provisions listed.
Front escort12'1" – 14'
One escort leads the load on two-lane/undivided highways (MDOT provision 12). Michigan's actual split is divided vs undivided roadway, approximated here as interstate vs non-interstate; on divided non-interstate highways the escort may instead follow (provision 11).
Front + Rear14'1"+
Front and rear escorts with radio communication (T-3 §G; provision 21). Statutory floor for mobile homes: MCL 257.719b requires 2 escorts on all 2-lane roads for Lower Peninsula homes wider than 14-1/3 feet. No permits over 14' wide during spring weight restrictions (T-2 §E). Over 16' wide is a superload (single-trip cap): case-by-case MDOT approval, Form 2465 route survey, possible police supervision. Above 20 ft, this row's escorts are the minimum; the permit sets any more.
Height
Permit required13'7" – 14'
No escort. Permittee must verify the route has been traveled to assure vertical clearance for any permit over 13'6" (T-2 §F).
Permit required14'1" – 14'6"
No escort or height pole required in this range; route-clearance verification still required (T-2 §F). MDOT's pole trigger is height exceeding 14'6" (provision 12).
Front + High pole14'7" – 15'
Front escort equipped with a fixed measuring device (height pole) set to assure clearance, required when height exceeds 14'6" (MDOT provision 12). For mobile homes, a load over 12' wide AND over 14'6" high requires front and rear escorts with the pole on the front escort (T-3 §G) — cross-dimension rule not expressible in single-dimension bands.
Front + Rear + High pole15'1"+
Rear escort added over 15' high (J.J. Keller); front escort carries the height pole (provision 12). Over 15' exceeds the single-trip cap and is a superload: MDOT case-by-case approval with Route Survey Certification (Form 2465); additional escorts/police supervision (provision 14) may be ordered. Above 20 ft, this row's escorts are the minimum; the permit sets any more.
Length
Permit required53'1" – 90'
Permit required; no escort up to 90' overall. Verified on MDOT-issued permit 125148087602 (75'0" overall): no escort provisions listed. Note: Michigan length legality is configuration-based (e.g., no overall cap for tractor-semitrailer with trailer ≤50'), so the 53' floor is an approximation inherited from the semitrailer limit.
Rear escort90'1" – 100'
One escort for overlength movements over 90' through 100' (J.J. Keller; rear placement per MDOT provision 11).
Front + Rear100'1" – 150'
Front and rear escorts over 100' (T-3 §G verbatim for mobile homes; J.J. Keller for general loads). Single-trip cap is 150' overall combination length (T-2 §I). Mobile homes/modules over 100' are capped at 105' overall including towing vehicle (T-3 §G).
Front + Rear150'1"+
Superload: over 150' exceeds the single-trip cap; MDOT case-by-case approval with Route Survey Certification (Form 2465). At least front and rear escorts; additional escorts/police supervision (provision 14) set per move. Above 200 ft, this row's escorts are the minimum; the permit sets any more.
On interstate
Escorts begin at 12'1" wide
Width
Permit required8'7" – 12'
Permit required over legal 8'6" width; no escort provision attaches at this width. Verified on MDOT-issued permit 125148087602 (10'0" wide): no escort provisions listed.
Rear escort12'1" – 14'
One escort follows the load on freeways/divided highways (MDOT provision 11; T-3 §G: rear escort for movements exceeding 12 feet and not more than 14 feet). Michigan's actual split is divided vs undivided roadway, approximated here as interstate vs non-interstate.
Front + Rear14'1"+
Front and rear escorts with radio communication to the hauling vehicle (T-3 §G; provision 21). No permits over 14' wide during the spring weight restriction period (T-2 §E). Over 16' wide exceeds the single-trip cap and is a superload: MDOT case-by-case approval, Route Survey Certification (Form 2465), and possible police supervision (provision 14). Above 20 ft, this row's escorts are the minimum; the permit sets any more.
Height
Permit required13'7" – 14'
No escort. Permittee must verify the route has been traveled to assure vertical clearance for any permit over 13'6" (T-2 §F).
Permit required14'1" – 14'6"
No escort or height pole required in this range; route-clearance verification still required (T-2 §F). MDOT's pole trigger is height exceeding 14'6" (provision 12).
Front + High pole14'7" – 15'
Front escort equipped with a fixed measuring device (height pole) set to assure clearance, required when height exceeds 14'6" (MDOT provision 12; J.J. Keller: 'Loads over 14 feet 6 inches high must be preceded by an escort vehicle equipped with a sensing device').
Front + Rear + High pole15'1"+
Rear escort added over 15' high (J.J. Keller); front escort carries the height pole (provision 12). Over 15' exceeds the single-trip cap and is a superload: MDOT case-by-case approval with Route Survey Certification (Form 2465); additional escorts/police supervision (provision 14) may be ordered. Above 20 ft, this row's escorts are the minimum; the permit sets any more.
Length
Permit required53'1" – 90'
Permit required; no escort up to 90' overall. Verified on MDOT-issued permit 125148087602 (75'0" overall): no escort provisions listed. Note: Michigan length legality is configuration-based (e.g., no overall cap for tractor-semitrailer with trailer ≤50'), so the 53' floor is an approximation inherited from the semitrailer limit.
Rear escort90'1" – 100'
One escort for overlength movements over 90' through 100' (J.J. Keller; rear placement per MDOT provision 11).
Front + Rear100'1" – 150'
Front and rear escorts over 100' (T-3 §G verbatim for mobile homes; J.J. Keller for general loads). Single-trip cap is 150' overall combination length (T-2 §I).
Front + Rear150'1"+
Superload: over 150' exceeds the single-trip cap; MDOT case-by-case approval with Route Survey Certification (Form 2465). At least front and rear escorts; additional escorts/police supervision (provision 14) set per move. Above 200 ft, this row's escorts are the minimum; the permit sets any more.
When a permitted load can move
- Standard hours
Daylight hours only, Monday through Friday. Daylight is one-half hour before sunrise to one-half hour after sunset.
- Night travel
Not permitted. MDOT issues both oversize and overweight permits for daylight hours only, so an overweight-only load gets no night allowance either.
- Weekend travel
Allowed all day Saturday and until 3 p.m. Sunday only for loads not exceeding 10 feet wide, 14 feet high and 90 feet long, and must be requested on the application. Mobile and modular homes are not eligible.
- Holiday restrictions
No movement from 12 noon the day before until daylight the first day after New Year's, Memorial Day, Independence Day, Labor Day, Thanksgiving and Christmas. For a Friday or Monday holiday the ban runs from noon before through daylight after the three-day weekend.
- Urban restrictions
When the permit lists this provision, no movement 7-9 a.m. or 3-6 p.m. in Genesee, Ingham, Jackson, Kalamazoo, Kent, Macomb, Muskegon, Oakland, Saginaw, Washtenaw and Wayne counties.
Signage Michigan expects
- Oversize load sign
Two OVERSIZE LOAD signs, 7 feet by 18 inches with 10-inch black letters on yellow, one on the front of the vehicle and one on the rear of the load. Mobile homes instead use a 6-foot-by-16-inch front sign and an 8-foot-by-18-inch rear sign.
- Flags
Overwidth or overlength loads require plain red or orange flags at least 18 inches square at each of the four corners, plus one at the widest point on each side if the load extends past a corner flag. Oversize mobile homes require six plain red flags.
- Beacons
At least two flashing or rotating amber lights on the extreme rear of the load when the permit lists that provision. Every escort vehicle carries at least one amber light on the roof. All amber lights must be visible for 500 feet.
Michigan permit office
The permit office is the authority on every number on this page. Call it, or open the official site, before you rely on a threshold for a load that is close to a line.
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What are the legal limits in Michigan without an oversize or overweight permit?
In Michigan, the legal limits without an oversize or overweight permit are 8'6" wide, 13'6" high, 53'0" long (semitrailer) and 80,000 lbs gross. Legal overhang is 3'0" front and 4'0" rear. Anything over those figures needs a permit from the Michigan permit office before it moves.
When does an oversize load need an escort or pilot car in Michigan?
On non-interstate in Michigan, escorts begin at 12'1" wide. On interstate, escorts begin at 12'1" wide. The first escort tier is "Front escort" at 12'1" – 14' wide. Every tier on this page quotes its rule and source.
Can oversize loads travel at night, on weekends or on holidays in Michigan?
Night travel: Not permitted. MDOT issues both oversize and overweight permits for daylight hours only, so an overweight-only load gets no night allowance either. Weekend travel: Allowed all day Saturday and until 3 p.m. Sunday only for loads not exceeding 10 feet wide, 14 feet high and 90 feet long, and must be requested on the application. Mobile and modular homes are not eligible. Holidays: No movement from 12 noon the day before until daylight the first day after New Year's, Memorial Day, Independence Day, Labor Day, Thanksgiving and Christmas. For a Friday or Monday holiday the ban runs from noon before through daylight after the three-day weekend.