Abstract: A combination of a mechanically driven chock and a truck trailer including a wheel chock having a bottom face, a top face, a slanted front face, and an arcuate rear face, the front face having a plurality of threaded bores formed therein, wherein a width of the wheel chock is equal to that of two wheels of the truck trailer in side-by-side relationship; and an air cylinder having a fixed portion coupled to an outer face of the mounting plate via a pair of brackets and situated at an angle of 45 degrees with respect to the horizontal and a movable portion having a length equal to that of the fixed portion and an inboard end slidably situated within the fixed portion and extendible rearwardly and downwardly only upon the actuation thereof, the movable portion of the air cylinder further including a square planar plate coupled at a central extent thereof to an outboard end thereof in perpendicular relationship therewith, the plate being screwably coupled to the front face of the chock, wherein a portion of the m