Michigan allows up to 160,000 GVW on their vehicles, which is generally double the 80,000GVW max in most states. However there are a few things to consider.
In order to carry that weight, trucks must have more axles. Most 80,000GVW trucks have 2 trailer axles, in order to carry the extra weight here, you need 8 axles. Reason, of course, is to keep the axle weight the same as any 2 axle truck on the road.
Of course, the 160K limit means you will need one truck, instead of 2, for the same amount of product, which, in theory, reduces the number of trucks on the road, and lessens congestion. Plus, heavy weight vehicles such as these get taxed at approx 3X the normal tax rates...so they are paying their fair share.
Not to mention, states like Ohio, Indiana etc are starting to embrace this concept. You can run heavy not these states as well.