Aunty is right about the weak dollar. The largest single cost increase has been due to the falling value of the dollar. Since Bush took office in 2000 the value of the dollar has fallen by half compared against the Euro. Look at the cost of oil in Euros instead of U.S. dollars and the picture doesn't look as bad.
Secondly the oil refinery capacity has not increased in the last 20 years and now that demand is out pacing supply of refined oil products the price has gone up and up. The oil companies are making record profits but they aren't investing in any more refining capicity. Why should they, they will make more money by reducing capicity.
Oil is traded on the world market and the Chineese and Indains are demanding more. With the new $2500 car India is developing the demand for oil will increase. Because of the increased wealth of the Chineese ( by our demand of their cheap goods) more of them will be able to afford drive.
Gas in Amsterdam is $7 a gallon, but pot is legal.