Intermodal shipments are poised to become the biggest source of revenue for railroads by the end of next year, according to a study funded by the Association of American Railroads (AAR). That means more competition for many long-haul trucking companies. According to AAR, intermodal industry expert Thomas Brown and independent Wall Street analyst Anthony Hatch found that rail intermodal shipments were up 8% over the past three months. They claim that growth rate positions intermodal to overtake coal as the top revenue source for railroads. Intermodal's growth trend has both good and bad consequences for trucking. On the one hand, large truckload carriers such as J.B. Hunt and Schneider National have developed dedicated intermodal subsidiaries to help them profit from intermodal freight growth.However, smaller long-haul trucking companies now find themselves competing with intermodal offerings from the rail industry, services now offered with 100% money-back guarantees if shipments don't reach their destination in time.