Petrol taxes in the US vs Europe

We have done quite a bit of traveling overseas in the past 3 years and are always amazed at how much higher petrol is. We have seen prices in the $6 – $8 per gallon range. The other thing we noticed is how much new and nicer all of the road infrastructure is. I decided to do a bit of research and discovered that most of the difference in the price lies in taxes. To my mind, this makes sense as it charges the users for repair and maintenance. In our country, the tax charged only covers a small portion of what is required and we rely on funds from both Federal and State budgets for the remainder. I suppose this accounts for the decline in the condition of our road infrastructure. Which system do you think is fairer and works better?