A heavy truck sales boom is predicted between 2004-06 as an improving U.S. economy, capacity crunch, and 2007 emission regulations force carriers to buy new equipment. Eli Lustgarten, managing director of financial investment firm H.C. Wainwright & Co. Inc., said several factors could spur truck sales to levels not seen since 1999-2000. Speaking at the Truck Renting & Leasing Assn.'s (TRALA) annual convention, he said the U.S. economy is expected to grow by 3% this year and 3% in 2004 before hitting higher levels of growth in 2005. At the same time, truck capacity is already at 90%, compared to 70% to 80% of the last few years, because the trucking industry contracted over the last two years. Lustgarten added that the last round of emission rules starting in 2007 will spur fleets to pre-buy trucks. "No one wants to be caught going into 2007 with 5-year-old equipment," he said. "Even trucks bought today will age three years between now and 2007. So truck sales will be exacerbated by the fear of 2007 emission changes."