Department of Transportation
MDOT
Michigan • United States of America
The Michigan Department of Transportation (MDOT) manages approximately 9,600 miles of state and US-route highways, including major automotive and industrial freight corridors I-75, I-94, I-96, I-196, I-69, and I-275. Michigan is the heart of the US auto industry, and MDOT's network supports just-in-time manufacturing supply chains for General Motors, Ford, and Stellantis. The department administers commercial vehicle permits, manages the Blue Water and Ambassador Bridge approaches at the US-Canada border, and operates the MiDrive travel information system. MDOT enforces weight limits during spring weight restriction season to protect road infrastructure from frost damage.
| Official Website | https://www.michigan.gov/mdot/ |
|---|---|
| Data API | https://www.michigan.gov/MDOT |
| Founded | 1905 |
| Headquarters | Detroit |
Available Data
Social Media
- @MichiganDOT — Michigan DOT
Michigan Trucking Regulations
Size & weight limits, OS/OW permits, and seasonal restrictions for commercial vehicles
Weight Limits
| Category | Limit |
|---|---|
| Max Gross Vehicle Weight | 80000 lbs |
| Single Axle | 18000 lbs |
| Tandem Axle | 32000 lbs |
Dimensional Limits
| Category | Limit |
|---|---|
| Max Height | 13.6 ft |
| Max Width | 8.5 ft |
| Max Length (Single Unit) | 40 ft |
| Max Length (Combination) | 65 ft |
OS/OW Permits
Seasonal Restrictions Feb, Mar, Apr, May
Michigan's frost law (spring weight restriction) program is one of the most impactful in the US. Postings typically begin in February and remain through May on affected state and local roads. Posted roads carry reduced weight limits (commonly a 25% reduction from standard). All carriers operating on secondary roads must check MDOT's frost law status before dispatching.
Weigh Station Bypass
26¢/gal
Member
Special Exemptions
Notable Rules
Michigan uses more restrictive standard axle limits on local and secondary roads (18,000 lbs single, 32,000 lbs tandem) versus the federal Interstate standard. On designated Level 2 and Level 3 routes with overweight permits, Michigan allows GVW significantly above 80,000 lbs. The Ambassador Bridge and Detroit-Windsor Tunnel are the busiest US-Canada commercial border crossings. Spring frost laws are strictly enforced and have significant fines.
Sources
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