Commercial Vehicles

Seasonal Weight Restrictions (Frost Laws) are now in effect. For a list of All-season roads please click here or view our Truck Operator's Map located here.

For information on restricted roads and bridges please see our Truck Operators Map (also see MDOT's Truck Operator's Map)

or see the All-Season roads list and the Restricted Bridges & Culverts list

For copies of permits required by the weighmaster please visit our permits section.

Michigan Truck Driver's Guidebook  

  Michigan Farmer's Transportation Guidebook

LOADING INFORMATION

NORMAL LOADING MAXIMUMS

18,000 lbs. on single axles spaced 9 ft. or more apart

13,000 lbs. on tandem axles spaced 3.5 ft. to 9 ft. apart

9,000 lbs. on axles separated by less than 3.5 ft.

13,000 lbs. per axle maximum, tri-axle and multi-axles.

 

DESIGNATED LOADING

16,000 lbs.  per axle on one tandem axle assembly

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SEASONAL RESTRICTION (Frost Law) LOADING MAXIMUMS  35% REDUCTION OF NORMAL LOADING PER AXLE (as follows):

11,700 lbs. on single axles spaced 9 ft. or more apart

8,450 lbs. on tandem axles spaced 3.5 ft. to 9 ft. apart

5,850 lbs. on axles separated by less than 3.5 ft.

8,450 lbs. per axle maximum, tri-axle and multi-axles.

35 mph maximum speed limit.

Frost law permits can be found here

ALL-SEASON ROAD LOADING MAXIMUMS

18,000 lbs. on single axles spaced 9 ft. or more apart

16,000 lbs. on tandem axles spaced 3.5 ft. to 9 ft. apart *Only one tandem axle assembly permitted @ 32,000 lbs., no other tandem axle assembly shall exceed 26,000 lbs.

9,000 lbs. on axles separated by less than 3.5 ft.

13,000 lbs. per axle maximum, tri-axles and multi-axles.

Weight determinations are based on axle configuration in the
Michigan Truck Safety Commission publication "Truck Driver's Guidebook" 

Historic Frost Law season periods

2002	1/23	to	3/25
2003	3/3	to	4/7
2004	2/26	to	3/29
2005	2/21	to	4/8
2006	Not used
2007	3/1	to	4/2
2008	2/25	to	4/9
2009	2/9	to	3/30
2010	2/26	to	3/24
2011	2/14	to	4/1