A system for reducing drag on a trailer includes a flexible membrane including a perimeter coupled to a rear end of the trailer. A variable-volume cavity is defined between the flexible membrane and the rear end. The system also includes a source of pressurized gas coupled to the trailer and in fluidic communication with the variable-volume cavity, and a controller operable to control a flow of the pressurized gas from the source to the variable-volume cavity such that the flexible membrane is moved from a stowed profile, wherein the flexible membrane is collapsed against the rear end of the trailer, to a first deployed profile, wherein the flexible membrane is maintained in a first pre-selected tapered aerodynamic shape projecting rearward from the rear end.