Michigan is home to the most permissive heavy-vehicle weight laws in the United States. While the federal interstate maximum is 80,000 lbs, Michigan allows gross vehicle weights up to 164,000 lbs on qualified 11-axle configurations on designated state routes — a product of longstanding concessions to the automotive manufacturing and steel industries that dominate the state's economy. The Michigan Office of Carrier Services, part of the Michigan Department of Transportation (MDOT), administers oversize/overweight permits and maintains the complex axle-to-weight table that governs legal operating weights. The I-75, I-94, I-96, and I-69 corridors serve auto plants, steel mills, and cross-border freight with Canada through the Ambassador Bridge and the Blue Water Bridge at Port Huron — among the busiest commercial crossings on the northern border. Michigan's extensive secondary road network, including low-posted-weight county roads common in the Upper Peninsula, adds complexity to routing decisions. The state enforces seasonal weight restrictions on non-designated routes during spring thaw. IRP credentials are issued through MDOT's Office of Carrier Services, and IFTA is administered by the Michigan Department of Treasury.
| GVWR | 164,000 lbs on 11-axle configurations on designated state routes (federal interstate standard is 80,000 lbs) |
| Single axle | 20,000 lbs (federal standard on Interstates); higher limits apply on state routes per Michigan's axle-weight table |
| Tandem axle | 34,000 lbs (federal standard); higher limits apply per Michigan's statutory table on designated routes |
Michigan's weight limits are the highest in the United States. The state uses a statutory axle-weight table — not a simple per-axle cap — to determine legal GVW based on number of axles and spacing. On non-designated routes and county roads, lower limits apply. Spring weight restrictions seasonally reduce allowable weights on non-Interstate routes.
State trucking association: Michigan Trucking Association
Michigan law (MCL 257.722) permits gross vehicle weights up to 164,000 lbs on 11-axle combinations on specifically designated state routes. The allowable weight is determined by a statutory table based on total axle count and inter-axle spacing — not a flat per-axle cap. Carriers must verify their configuration meets the table requirements and that their route includes only MDOT-designated segments. This does not apply on federal Interstates, where the 80,000 lb federal standard applies.
No. The elevated Michigan weight limits (up to 164,000 lbs) apply only on designated state routes, not on federal Interstate highways. On Interstates, the standard federal maximum of 80,000 lbs GVW applies. Carriers operating 11-axle configurations must route exclusively on MDOT-designated non-Interstate segments for the higher limits to apply.
Commercial vehicles crossing into Canada via the Ambassador Bridge (Detroit–Windsor) or Blue Water Bridge (Port Huron–Sarnia) must file an ACE electronic manifest with U.S. CBP prior to departure, comply with Canada Border Services Agency (CBSA) entry requirements, and meet Transport Canada vehicle standards. FAST lane programs are available for pre-approved carriers and drivers.
The Michigan Department of Treasury administers IFTA licensing and quarterly fuel use reporting. IRP apportioned vehicle registration and oversize/overweight permits are handled by the Michigan Department of Transportation's Office of Carrier Services.