A hopper trailer, sometimes referred to a grain trailer, is used to haul bulk commodities. These trailers are used extensively throughout the USA to transport agricultural products and other commodities. Hopper trailers typically feature a rolling tarp on the top of the trailer. This enables easy loading of the product to be transported and also offers protection during transport. The easily operated crank handle engages sliding plates at the bottom of the hopper allowing product to fall out when the operator turns the crank handle.
Prime advantage is that it is typically one of the least costly per pound ways of transportation.