A retractable barrier system includes an example gear assembly that can be manipulated for rapidly deploying a flexible barrier, exerting high torque for the initial tightening of the barrier, maintaining high static tension in barrier when in use, and/or rapidly retracting barrier for storage. In some examples, the gear assembly is a worm drive with a worm that can be selectively disengaged from a worm gear. Other optional features of the barrier system include selective right-hand/left-hand configurations, an electric switch that can be added to indicate whether the barrier system is in use, an intermediate coupling that joins the distal ends of two barriers for creating an extra long barrier system, and removable vehicle-mounted posts for certain loading dock applications.