In 1898, Hyman Shear began operating a drayage company known as H. Shear Trucking Company. XPO combines railroad and truck (drayage) transportation. They were already in the freighting and drayage business. Hub Group acquired Memphis, Tennessee-based drayage company Comtrak Logistics for $48 million in 2006. Diesel-powered harbor short-haul (drayage) trucks are a major source of air pollution. A drayage company and draymen provide carriage from or to a port or railway ramp. The term drayage is also used for the fee paid for such services. Various interest groups began realizing the influence of drayage.