Diesel costs are reaching new highs across the U.S., straining the operations of trucking companies and wrecking the transportation budgets of businesses that need to ship goods. The price of the fuel that powers heavy-duty trucks has increased by more than $1.50 a gallon in roughly two months, according to the U.S. Energy Information Administration. The national average price has climbed to $5.62 a gallon, setting a record for the second week in a row, as prices at the pump surpassed $6 in some markets. “These fuel costs are the biggest thing we’re facing right now,” said Jake Phipps, chief executive of Phipps & Co., a West Palm Beach, Fla.-based manufacturer of interior finishes and building materials for real-estate developers. He said the company’s shipping costs within the U.S. have risen 15% to 20% from last year, […]