The invention relates to a system for supervising access to a restricted area, including at least one obstacle that is mobile between a deployed configuration, in which said obstacle extends across a passageway for the entry and/or exit to/from said restricted area, and a stowed configuration in which said obstacle is removed from said passageway. The system also includes a unit for driving the obstacle between the deployed configuration and the stowed configuration, a device for measuring the position of the obstacle, and a module for controlling the drive unit. The control module is suitable for comparing the measured position of the obstacle at at least one moment in time with a theoretical position of the obstacle at said moment in time, and to derive a rule for controlling the drive unit.