There was a study done that I read earlier this year that showed that we do have higher than nation average wages, but it wasn't that much higher than the national average. One of the states (in the Midwest I think) pay around 20k a mile and have wages sitting 7-17% higher than the national average.

The 3 highest cost per mile states are NJ at 200k, MA at 145k, and HI at 86k (i think that was the number).

I will have to look for the article again (I will link it to you if I have time to find it), but worker labor costs are not the reason our roads cost so much to maintain.