The system includes a capturing device for capturing information regarding presence from the exterior, representative of an object included within a supervisory area, which operates in combination with a device for detecting trajectories and a device for detecting inclinations of the vehicle, associated and in cooperation with an electronic system. The method includes using the proposed system to, by the generation of a chart that relates the trajectory and/or inclination with a corresponding supervisory area to be covered by the capturing device, vary the supervisory area depending on the trajectory and/or inclination of the vehicle, through the selection and execution of the appropriate actions, by the electronic system, which will depend on the type of capturing device used.