The vast majority of road wear and tear is caused by trucks, not cars:
"Heavy trucks obviously cause more road damage than cars, but how much more? According to a GAO study, Excessive Truck Weight: An Expensive Burden We Can No Longer Afford, road damage from one 18-wheeler is equivalent to 9600 cars (p.23 of study, p.36 of PDF)."
With regards to your point to taxes, remove the per-milage tax and charge a flat per-vehicle rate based on vehicle class, distributing the cost to trucks more than to passenger vehicles.
"Heavy trucks obviously cause more road damage than cars, but how much more? According to a GAO study, Excessive Truck Weight: An Expensive Burden We Can No Longer Afford, road damage from one 18-wheeler is equivalent to 9600 cars (p.23 of study, p.36 of PDF)."
http://archive.gao.gov/f0302/109884.pdf
http://facweb.knowlton.ohio-state.edu/pviton/courses2/crp776...
With regards to your point to taxes, remove the per-milage tax and charge a flat per-vehicle rate based on vehicle class, distributing the cost to trucks more than to passenger vehicles.