Method for warning the driver of a motor vehicle of an impending hazardous situation caused by accidental drifting towards or into a lane of oncoming traffic, characterised in that: - a virtual vehicle path which is oriented in the direction of travel of the motor vehicle in question is determined, - using an in particular optical detection sensor, a lane marker separating the lane in question from the lane of oncoming traffic is determined, - the relative position of the motor vehicle in question in relation to the lane marker is determined, - using a detection sensor, more particularly a radar sensor, any oncoming vehicle travelling in the lane of oncoming traffic is determined, - a check is carried out as to whether the oncoming vehicle will enter or has entered the virtual vehicle path, - a check is carried out as to whether the motor vehicle in question will cross or has crossed the lane marker based on the given relative position of said motor vehicle in relation thereto, - the presence or absence of one or more items of sensor information indicating an active travel operation, more particularly a steering operation by the driver, and thus indicating that the detected relative position of the motor vehicle is reached as a result of driver activity, is checked and - a warning signal is output and/or an automatic driving mode intervention is carried out when results of the checks indicate that the oncoming vehicle will enter or has entered into the virtual vehicle path and the vehicle in question will cross or has crossed the lane marker, thus making a collision likely, and when the sensor information rules out an active steering operation by the driver, - a warning and/or intervention only being carried out when the lane marker separating the lane in question from the lane of oncoming traffic is continuously detected for a predetermined, optionally adjustable period of time and/or - a warning and/or intervention only being carried out when no additional marker which is located closely adjacent to the lane marker separating the lane in question from the lane of oncoming traffic is detected within a predetermined or adjustable period of time. - a virtual vehicle path which is oriented in the direction of travel of the motor vehicle in question is determined, - using an in particular optical detection sensor, a lane marker separating the lane in question from the lane of oncoming traffic is determined, - the relative position of the motor vehicle in question in relation to the lane marker is determined, - using a detection sensor, more particularly a radar sensor, any oncoming vehicle travelling in the lane of oncoming traffic is determined, - a check is carried out as to whether the oncoming vehicle will enter or has entered the virtual vehicle path, - a check is carried out as to whether the motor vehicle in question will cross or has crossed the lane marker based on the given relative position of said motor vehicle in relation thereto, - the presence or absence of one or more items of sensor information indicating an active travel operation, more particularly a steering operation by the driver, and thus indicating that the detected relative position of the motor vehicle is reached as a result of driver activity, is checked and - a warning signal is output and/or an automatic driving mode intervention is carried out when results of the checks indicate that the oncoming vehicle will enter or has entered into the virtual vehicle path and the vehicle in question will cross or has crossed the lane marker, thus making a collision likely, and when the sensor information rules out an active steering operation by the driver, - a warning and/or intervention only being carried out when the lane marker separating the lane in question from the lane of oncoming traffic is continuously detected for a predetermined, optionally adjustable period of time and/or - a warning and/or intervention only being carried out when no additional marker which is located closely adjacent to the lane marker separating the lane in question from the lane of oncoming traffic is detected within a predetermined or adjustable period of time.