Deployable fairing for use with vehicles

Systems and methods that provide a deployable fairing system to a tractor trailer. The deployable fairing system includes an actuator used to extend the deployable fairing from an unextended configuration to an extended configuration to occupy a portion of a gap area that exists between a tractor and an attached trailer. The deployable fairing includes deployable upper and/or lower horizontal assemblies that are pivotally coupled to a frame attached to the tractor/cab, and two side panels that are pivotally coupled to one or both of the upper and lower horizontal assemblies. The deployable upper and lower horizontal assemblies and the two side panels fold in on one another along multiple hinged axes in the unextended configuration, and extend rearward from the top and sides of the tractor in the extended configuration to cover a portion of the gap. The fairing may advantageously flair from front to the rear.