System for measuring and visualizing the occupancy of truck parking lots, operating on the principle of accumulating the arrivals and departures of vehicles. The system is adapted for operation at highway parking lots. The key element of the system is a special set of sensors (cameras and lidars), for vehicle detection, determination of its type (truck, bus, van, passenger car with trailer, passenger car, motorcycle), direction of motion and information allowing re-identification (e.g. registration number, manufacturer, model version, 3D silhouette). The system uses a statistical model to dynamically correct the current parking lot occupancy, giving the user a precise real-time readout of number of free spots.