When Cynthia Miller moved to Houston at the start of the year, she planned to make the 260-mile drive back to visit friends and family in Baton Rouge once every three weeks. But with petrol prices approaching $4 a gallon, such a trip is now a luxury.

“I really was hesitant about going home for Easter,” said Ms Miller, an assistant account executive at Hill and Knowlton, the public relations consultancy.