MI state page · Last reviewed 2026-05-25
Michigan Truck Weight Limits and Permit Sources Michigan truck weight and MDOT permit reference with special attention to seasonal and frost restriction review.
This page is a reference aid, not legal advice. Weight rules, permits, routes,
and penalties can change without notice; use the linked official source as the
final authority.
At-a-glance summary Field Value Source Status Confidence Gross Federal Interstate gross limit is 80,000 lb; Michigan-specific limits are in the FHWA state law compilation linked here. inferred from official source medium Single axle Federal Interstate single-axle limit is 20,000 lb; Michigan-specific limits are in the FHWA state law compilation linked here. inferred from official source medium Tandem axle Federal Interstate tandem limit is 34,000 lb; Michigan-specific limits are in the FHWA state law compilation linked here. inferred from official source medium Bridge formula Federal bridge formula checks apply on Interstate routes; verify state exceptions and permit conditions before movement. inferred from official source medium Permit agency Michigan Department of Transportation confirmed high Seasonal / frost Michigan publishes seasonal weight restrictions and frost-law information through MDOT; current restrictions must be checked before travel. confirmed medium Fine source Official fine structure not confirmed in this review. No confirmed official source Needs official confirmation
not found in official review low
Field-level reference data Regular weight limits Gross vehicle weight limit Federal Interstate gross limit is 80,000 lb; Michigan-specific limits are in the FHWA state law compilation linked here. inferred from official source medium Single axle limit Federal Interstate single-axle limit is 20,000 lb; Michigan-specific limits are in the FHWA state law compilation linked here. inferred from official source medium Tandem axle limit Federal Interstate tandem limit is 34,000 lb; Michigan-specific limits are in the FHWA state law compilation linked here. inferred from official source medium Bridge formula applies Federal bridge formula checks apply on Interstate routes; verify state exceptions and permit conditions before movement. inferred from official source medium Interstate notes Use FHWA Interstate limits together with the state source and any permit conditions. inferred from official source medium Non-Interstate notes Use the reviewed state source and local postings for non-Interstate operation. inferred from official source medium
Axle and loading notes Steer axle notes Steer axle review should include axle law, tire/equipment ratings, registration, and route postings. inferred from official source medium Drive axle notes Drive axle groups should be checked against tandem/group limits and permit terms. inferred from official source medium Trailer tandem notes Trailer tandem position changes distribution and may affect spacing-sensitive checks; re-weigh after adjustment. inferred from official source medium Fifth wheel notes Fifth-wheel movement redistributes weight but does not create permit authority. inferred from official source medium Bridge law notes Check FHWA bridge formula and the state source when axle spacing is close to a limit. inferred from official source medium
Oversize / overweight permits Permit agency Michigan Department of Transportation confirmed high Permit office name MDOT Transport Permits confirmed high Official permit URL MDOT transport permits page. confirmed high Online permit portal Use MDOT's official permit source for current online permit access. inferred from official source medium Permit contact Use MDOT contacts on the official transport permit page. inferred from official source medium Permit notes Permit terms, route conditions, dates, and vehicle configuration should be checked on the official permit source before travel. inferred from official source medium
Seasonal and special restrictions Frost / seasonal restriction Michigan publishes seasonal weight restrictions and frost-law information through MDOT; current restrictions must be checked before travel. confirmed medium Seasonal weight notes Use MDOT seasonal weight restriction materials for current route-level and seasonal limits before travel. confirmed medium Official seasonal URL MDOT seasonal weight restrictions source. confirmed medium
Fines and enforcement Overweight fine structure Official fine structure not confirmed in this review. No confirmed official source Needs official confirmation
not found in official review low Overweight ticket notes Use the actual citation, current statute, and permit terms before estimating penalties. No confirmed official source Needs official confirmation
not found in official review low Enforcement agency Official enforcement agency page not confirmed in this review. No confirmed official source Needs official confirmation
not found in official review low Fine official URL No confirmed official source Needs official confirmation
not found in official review low CSA / safety notes CSA impact depends on inspection and reporting; use FMCSA SMS materials and the actual inspection record. inferred from official source medium
Scale notes Public scale notes A public scale ticket is a self-check record, not state permit authority. inferred from official source medium Weigh station / enforcement notes Compare scale readings with official limits, route postings, and any permit terms. inferred from official source medium CAT Scale disclaimer CAT Scale tickets are private self-check records and do not replace official permits or enforcement decisions. inferred from official source medium Scale ticket notes Use steer, drive, trailer, and gross readings to compare against official limits before travel. inferred from official source medium
Michigan’s Great Lakes peninsula geography means that freight entering or leaving the Lower Peninsula crosses at limited points — the Mackinac Bridge for Upper Peninsula access, and I-75 and I-94 for Michigan-Ohio and Michigan-Indiana connections. MDOT administers transport permits, and Michigan’s seasonal spring weight restrictions are among the most formally structured in the Midwest: MDOT publishes restriction start and end dates by route category each year. Oversized loads crossing the Mackinac Bridge have specific size and wind-advisory conditions applied by the Mackinac Bridge Authority separately from MDOT permit terms.
How to verify this yourself
Use MDOT transport permits for OS/OW movement and MDOT seasonal weight restriction materials for current frost or seasonal load conditions. For Mackinac Bridge crossings, verify advisory conditions on the Bridge Authority source separately.
FAQ Where should I verify Michigan permit requirements? Use the official MDOT Transport Permits source linked on this page before moving over legal size or weight.
Are Michigan seasonal restrictions fully confirmed here? The linked official source should be checked for current seasonal, route, or permit restrictions.
Are these weight values accurate for Michigan roads beyond the Interstate system? The values shown are the federal Interstate baseline. State-specific non-Interstate limits are in the FHWA state law compilation linked here and may differ from the baseline.