Gasoline prices in the United States are at the highest level seen at this time of year in over a decade ― and could soon climb even higher. After a summer of increases that plateaued only briefly over the past two weeks, prices may soon lurch upward again in response to cuts to the global supply or if more disastrous storms lash the U.S. Gulf Coast. The price at the pump typically tracks the cost per barrel of crude oil, which is the main ingredient in fuel for automobiles. On Tuesday, the price of Brent crude ― the benchmark for oil refined in Western Europe ― surged past $90 per barrel for the first time this year. The spike came shortly after the world’s top two oil exporters, Saudi Arabia and Russia, announced plans to cut back on supply. The price of West Texas Intermediate ― the be...