A system for a vehicle, having a head-up display, having a central unit having a circuit connected to the head-up display, having an internal camera configured for capturing a driver's face and sending image data to the central unit for evaluation; wherein the central unit is configured to recognize a driver's eyes and to ascertain a position of the driver's eyes concurrently based on the image data, and having a recording means for recording first image data of the surroundings of the vehicle, whereby the recording means is connected to the circuit, wherein the circuit is configured to recognize an object (457, 458, 459) in the surroundings based on the recorded first image data, the object being one of a road marking, curb, wall, road user, and "no entry" traffic sign placed at the exit end of a one-way street, and wherein the head-up display is configured to project an image onto a windshield or onto a combiner of the vehicle in the field of view of the driver, wherein the circuit is configured to generate second image data for outputting the image and to send them to the head-up display, wherein the circuit is configured to generate a virtual barrier in the second image data when a warning signal exceeds a threshold, wherein the virtual barrier comprises a virtual wall or a row of traffic cones, wherein the circuit is configured to generate the warning signal based on a determined distance of the vehicle to the object (457, 458, 459), and wherein the circuit is configured to position the virtual barrier within the image based on a determined position of the recognized object (457, 458, 459), whereby the positioned virtual barrier in a view direction of the driver to the recognized object (457, 458, 459) overlaps the recognized object (457, 458, 459) at least partially. having a head-up display, having a central unit having a circuit connected to the head-up display, having an internal camera configured for capturing a driver's face and sending image data to the central unit for evaluation; wherein the central unit is configured to recognize a driver's eyes and to ascertain a position of the driver's eyes concurrently based on the image data, and having a recording means for recording first image data of the surroundings of the vehicle, whereby the recording means is connected to the circuit, wherein the circuit is configured to recognize an object (457, 458, 459) in the surroundings based on the recorded first image data, the object being one of a road marking, curb, wall, road user, and "no entry" traffic sign placed at the exit end of a one-way street, and wherein the head-up display is configured to project an image onto a windshield or onto a combiner of the vehicle in the field of view of the driver, wherein the circuit is configured to generate second image data for outputting the image and to send them to the head-up display, wherein the circuit is configured to generate a virtual barrier in the second image data when a warning signal exceeds a threshold, wherein the virtual barrier comprises a virtual wall or a row of traffic cones, wherein the circuit is configured to generate the warning signal based on a determined distance of the vehicle to the object (457, 458, 459), and wherein the circuit is configured to position the virtual barrier within the image based on a determined position of the recognized object (457, 458, 459), whereby the positioned virtual barrier in a view direction of the driver to the recognized object (457, 458, 459) overlaps the recognized object (457, 458, 459) at least partially.