About two years ago, Raven Transport started switching its over-the-road tractor fleet to operate on liquefied natural gas. It expects to be running 100% on LNG by 2019. Stephen Silverman, chief operating officer of the Jacksonville, Fla.-based truckload carrier, explains the transition was driven by three factors: addressing customers’ sustainability goals, contributing to U.S. energy independence, and lowering fuel costs for the 500-truck fleet. “When we began buying LNG tr