A trailer for carrying unit load devices (ULDs), including unloaded and/or loaded containers and pallets, or other cargo; the trailer designed to be towed on surface streets and highways by conventional motorized truck-tractor units. The trailers are equipped with adjustable decks for supporting ULDs in stacked configuration on the trailer. Using a lowered well portion permits selected ULD stacks to not exceed legal trailer height limits so that additional permitting is not required.