The highest retail gasoline prices in years are the latest development to raise concerns about one of the longest-running U.S. economic expansions on record. Drivers across the U.S. in May paid as much as $2.96 a gallon on average, the most since 2014. Prices have climbed to $3.63 in California and $3.39 in Washington, states where prices tend to be higher because of factors such as higher taxes, environmental regulations and a lack of pipelines that transport oil west. As of Monday, the national average was $2.86 a gallon. With wages in the U.S. climbing , Americans have so far been able to weather the higher prices. But analysts say that if average gas prices hit $3.50 or even $4 a gallon as global oil prices rise, that could dent growth by eating into disposable income and spending. Some analysts say the recent run-up hasn’t pinched Americans too much. […]