BNSF Railway reported stronger first-quarter profits as higher volume and more efficient operations improved the railroad’s bottom line. Pre-tax income rose 13.5%, to $1.82 billion, as revenue increased 5%, to $5.92 billion, BNSF’s corporate parent, Berkshire Hathaway (NYSE: BRK-B), reported on Saturday morning. The railroad’s operating ratio improved 2.3 points to 65.6% as improved fuel efficiency and labor productivity more than offset higher fuel prices and wages. Overall volume increased 2.2% thanks ...