Early Friday evening, Jay Robinson, a Dallas insurance adjuster, pulled into his local QuikTrip gas station for a coffee break. As he filled his cup, drivers stopping at the pumps confronted prices that had spiked more than 30 percent since the outbreak of war in Iran. Mr. Robinson, 42, has been hit by those price increases harder than most. With his wedding not too far off, he has been moonlighting as a ride-share driver to help cover the costs. But the war — and the subsequent throttling of global oil supplies — have cut into his margins. “I’m already getting taxed by inflation, and this is not helping,” Mr. Robinson said. Even with the solid gas mileage on his car, a 2019 Toyota Corolla, he said the climbing prices had been impossible to ignore. “I hope that it ends soon,” he said. After a U.S. and Israeli missile barrage sparked the Iran war in late February, Iran retaliated by closing the Strait of Hormuz, a vital choke point at the mouth of the Persian Gulf. A quarter of the world’s oil supply passes through the strait. The passageway’s closure has sharply constricted that supply and, for U.S. drivers, led to rapid increases in gas prices.