Michigan State Regulations
Transportation Restrictions
The following holidays are restricted: New Year’s Day, Memorial Day, Independence Day, Labor Day, Thanksgiving, and Christmas. When a holiday falls on a Friday or Monday, movement stops at noon before the three-day weekend, and movement resumes sunrise the day after the three-day weekend.
Movement restricted from 7:00 AM to 9:00 AM and from 3:00 PM to 6:00 PM in the following counties: Genesee, Ingham, Jackson, Kalamazoo, Kent, Macomb, Muskegon, Oakland, Saginaw, Washtenaw, and Wayne.
Spring Weight Restrictions
Usually February to April normal maximum axle weights allowable on rigid pavements shall be reduced 25%. On flexible pavements the maximum axle weights are reduced 35%. Generally, no overweight permits are issued during spring frost restrictions.
Operating Time
Weekend Travel
Weekend travel is allowed if overall loaded dimensions do not exceed 10′ in width, 14′ in height, and 90′ in overall length. Weekend travel includes daylight Saturday and Sunday daylight hours until 3:00 PM.
Transportation Requirements
Provision Regulations
Superloads
Anything over Routine Issue dimensions requires special approval from the DOT.
Oversize Load Signs
“Oversize Load” signs required on front of vehicle and on rear of load for any overdimensional load.
Flags/Lights
18” red flags required for any overhang over 4’ and at the four corners and widest point of any oversize load.
2 flashing or rotating amber lights are required at the extreme rear of any oversize load.
Blades
Can haul dozer, loader, etc., with blades or buckets attached to the load.
Legal Limits
| Component | Restriction |
|---|---|
| Width | 8’6″ on Designated Highways, 8′ on Non-Designated Highways |
| Height | 13’6″ |
| Length – Truck-Tractor & Semi-Trailer | No Limitation* |
| Length – Single Vehicle | 40′ (Excluding Impact Absorbing Bumpers) |
| Length – Semi-Trailer | 53′ on Designated Highways, 50′ on Non-Designated Highways |
| Length – Truck & Semi-Trailer | 65′ on Designated Highways, 59′ on Non-Designated Highways |
| Front Overhang | 3′ |
| Rear Overhang | Any amount is permissible if the legal length is not exceeded. However, if this overhang is 4 feet or more, there shall be displayed on the extreme rear of such a load a 12 – inch red square flag in the daytime and a red light or lantern at night. |
| Axle Limitation | A combination of vehicles shall not exceed 11 axles |
| Single Axle – Axle Spacing of 9′ or More | 18,000 lbs. if Over 80,000 lbs Gross Weight, 20,000 lbs. if Under 80,000 lbs. Gross Weight |
| Single Axle – Axle Spacing More Than or Equal to 3’6″ but Less Than 9′ | 13,000 lbs. if Over 80,000 lbs Gross Weight |
| Single Axle – Axle Spacing Less Than 3’6″ | 9,000 lbs. if Over 80,000 lbs Gross Weight |
| Tandem Group | 16,000 lbs. Per Axle if Over 80,000 lbs Gross Weight** |
| Tandem Group | 34,000 lbs. if Under 80,000 lbs. Gross Weight |
| Pounds per inch of tire width | 700 lbs. |
*Provided semi-trailer lengths do not exceed limits for non-designated and designated highways.
Length of semitrailers longer than 50 feet shall have a wheelbase of 37 feet to 41 feet (measured from the kingpin coupling to the center of the rear axle or to the center of the rear axle assembly).
**On any legal combination of vehicles, only one (1) tandem axle assembly shall be permitted at the gross weight of 16,000 lbs. per axle and no other tandem axle assembly in such combination of vehicles shall exceed a gross weight of 13,000 lbs. per axle. On a combination of a truck tractor and semitrailer having not more than 5 axles, two (2) consecutive tandem axle assemblies shall be permitted at a gross permissible weight of 16,000 lbs. per axle, if there is no other axle within 9 feet of any axle of the assembly.
Routine Issues
| Component | Restriction |
|---|---|
| Axle Weights | Follow Federal Bridge Formula |
| Gross Weight | 164,000 lbs. |
| Width | 16′ (14′ During Spring Restrictions) |
| Height | 15′ |
| Length | 150′ |
Escort Requirements
| Dimension | Requirement |
|---|---|
| Width Over 12′ – 14′ | 1 Front on 2-Lane Highways, 1 Rear on 4-Lane Highways |
| Width Over 14′ | 2 (Front & Rear) |
| Height Over 14’5″ – 15′ | 1 Front with High Pole |
| Height Over 15′ | 2 (Front & Rear) |
| Length 90′ – 100′ | 1 Front on 2-Lane Highways, 1 Rear on 4-Lane Highways |
| Length Over 100′ | 2 (Front & Rear) |
| Over 15′ Rear Overhang | 1 Rear |