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 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 (S3) 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 (S3) based on a determined distance of the vehicle to the object , and wherein the circuit is configured to position the virtual barrier within the image based on a determined position of the recognized object , whereby the positioned virtual barrier in a view direction (VD) of the driver to the recognized object overlaps the recognized object 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 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 (S3) 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 (S3) based on a determined distance of the vehicle to the object , and wherein the circuit is configured to position the virtual barrier within the image based on a determined position of the recognized object , whereby the positioned virtual barrier in a view direction (VD) of the driver to the recognized object overlaps the recognized object at least partially. <EOS>