Michigan Truck Weight and Size Limits
Legal limits for a truck in Michigan without a permit: Interstate axle and gross weights, height, width, and semitrailer length, each with its official source.
Michigan limits at a glance
| Limit | Michigan | Source |
|---|---|---|
| Interstate gross weight | 80,000 lb | FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendices A and B |
| Interstate single axle | 20,000 lb | FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendices A and B |
| Interstate tandem axle | 34,000 lb | FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendices A and B |
| Width (National Network) | 102 in | 23 CFR 658.15, Width (eCFR) |
| Height | 13 ft 6 in | Mich. Comp. Laws § 257.719(1) |
| Semitrailer length | 50 ft; 53 ft on designated highways | Mich. Comp. Laws § 257.719(2)(d), (3)(a) |
| Grandfathered semitrailer length | 48 ft | 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) |
Interstate weight limits
Federal law sets the Interstate limits at 20,000 lb on a single axle, 34,000 lb on a tandem, and 80,000 lb gross, with the bridge formula on every axle group (23 CFR 658.17). States may keep higher limits they had before the federal limits took effect ("grandfather rights").
These limits apply to trucks grossing 80,000 lb or less, which must meet the bridge formula. Michigan allows up to 164,000 lb on the Interstate and designated highways under its own lower axle limits (18,000 lb single, 13,000-16,000 lb per tandem axle).
FHWA on Michigan: Michigan has a grandfather provision under Federal law (23 CFR Part 658, Appendix C) to allow vehicles to operate up to 164,000 lbs. GVW on the Interstate System provided axle limits are maintained. See the Routes section for a full description of the routes to which this grandfather provision applies.
Bridge formula check with Michigan limits
A 5-axle tractor-trailer is filled in. Change the spacings and weights to match your rig; the limits for single axles, tandems, and gross are Michigan's Interstate limits.
Your result
Michigan limits off the Interstate
FHWA's summary of Michigan law for trucks in regular operation (no permit), including non-Interstate highways. It reflects state law as of October 1, 2012; check the state for later changes.
- Single axle
- 20,000 lbs. on Interstate highways or other designated highways for vehicles with a GVW of 80,000 lbs. or less / 18,000 lbs. on all other highways (spaced 9 ft. or more apart) / 9,000 lbs. on all other highways (spaced less than 3 ft. 6 inches)
- Tandem axle
- 34,000 lbs. on Interstate highways or other designated highways for vehicles with a GVW of 80,000 lbs. or less / Each axle of a tandem assembly is limited to 13,000 lbs. on all other highways, except in the following cases: / One axle may carry up to 16,000 lbs. if there is no other axle within 9 ft. of any axle of the assembly and no other axle in the vehicle combination exceeds 13,000 lbs. / Two consecutive tandem axles may carry up to 16,000 lbs. each if there is no other axle within 9 ft. of any axle of the assembly and the vehicle is a truck tractor-semitrailer combination having not more than five axles.
- Tridem axle
- Per State weight table
- Gross weight
- 80,000 lbs. or less: application of bridge formula / More than 80,000 lbs., provided axle limits are maintained (up to 164,000 lbs. on 11 axles and appropriate spacing).
- Other
- 700 lbs. per inch of tire tread width
Where Michigan allows more than federal limits
- Michigan State statute allows for several axle and GVW exemptions for various types of vehicles and commodities.
- Weight laws do not apply to boat lifts operated by a marina or watercraft dealer when moved incidentally on the highway.
Height, width, and length
- Width: 102 inches. States may not set a width limit of more or less than 102 inches on the National Network (23 CFR 658.15(a)). Permits can allow wider loads.
- Height: 13 ft 6 in. There is no federal height limit; each state sets its own.
- Semitrailer length: 50 ft; 53 ft on designated highways
- Grandfathered semitrailer length: 48 ft. The minimum semitrailer length the state must allow in a tractor-semitrailer combination on the National Network, based on lengths legal in the state on December 1, 1982. Federal law also requires at least 48 ft (23 CFR 658.13(b)(1)).
Over these limits you need a permit. Michigan oversize/overweight permits (517-241-8999).
Michigan compared with neighboring states
| State | Gross | Single | Tandem | Height | Semitrailer |
|---|---|---|---|---|---|
| Michigan | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 50 ft |
| Indiana | 80,000 lb | 20,000 lb | 34,000 lb | Pending | Pending |
| Ohio | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 53 ft in a tractor-semitrailer combina… |
| Wisconsin | 80,000 lb | 20,000 lb | 34,000 lb | 13 ft 6 in | 53 ft if the kingpin to axle distance … |
Sources
Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendices A and B · Effective Oct 1, 2012 · Last verified Sep 28, 2026
Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix A: Michigan · Effective Oct 1, 2012 · Last verified Sep 28, 2026
Source: 23 CFR 658.15, Width (eCFR) · Last verified Sep 28, 2026
Source: 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) · Last verified Sep 28, 2026
Source: Mich. Comp. Laws § 257.719(2)(d), (3)(a) · Last verified Sep 28, 2026
Source: FHWA, Oversize/Overweight Load Permits: State permit contacts · Last verified Sep 28, 2026
Limits change, and cities, counties, and posted bridges can set lower ones. Check with Michigan before you run a load near the limits. Page data last verified Sep 28, 2026.