“....I can’t understand why they haven’t been able to improve asphalt to better withstand the weather conditions and truck traffic here in Michigan. It’s almost like planned obsolescence....”
Actually its about the road base and sub base.
Drainage is key. When water gets under the asphalt, the base or sub base begin to erode and creates a void. Asphalt is not capable to support structural loads.
Clay is the worst. Expansion and contraction thing.
Being an architect I’ve played with this issue for 40 years.
Bottom line. It’s all about money. You don’t see potholes on the interstate. They have money and other assets. ..
God bless.