For Allowable Vehicle (Truck) Loading in Michigan Refer to Michigan Compiled Laws Section 257.722.  The following information shall only serve as a quick abbreviated guide and does not supersede any rules or laws of the Michigan Compiled Laws previously referenced.

Maximum allowable gross axle loading on All-Season Routes are:
Single Axle:  18,000 lbs.
Tandem Axle:  16,000 lbs./each axle
Any other axle having another axle within 9 feet: 13,000 lbs./each axle

Maximum allowable gross axle loading on all weight restricted roadways (NOT All-Season Routes) are:
Single Axle:  11,700 lbs.
Tandem Axle:  10,400 lbs./each axle
Any other axle having another axle within 9 feet: 8,450 lbs./each axle
(On any legal combination of vehicles only one (1) tandem axle assembly shall be permitted at the gross weight of 10,400 lbs. per axle and no other tandem axle assembly in such combination of vehicles shall exceed a gross weight of 10,400 lbs. per axle.)
Maximum load on any tire shall not exceed 450 lbs. per inch of tire width.  Maximum speed 35 MPH for trucks over 10,000 lbs. GVW.