How much would MPG ratings change in cars if they included the cost of road building and maintenance?

So, when people think about car efficiency, I’m curious how much of a difference roads themselves make.

It seems like roads crews are constantly ripping up roads and filling pot holes… if you amortized the amount of energy/cost/time for all this road building, how much would it lower the “absolute MPG” (assuming you can convert energy and cost into the efficiency of MPG). Would it make a significant difference, or are there enough cars to mostly factor it out?