In a method for identifying a danger zone to be monitored at a grade crossing, the following are performed: at least one radar sensor is situated at the danger zone; object trajectories from sequences over time of object positions of respective objects moving through the danger zone are ascertained by the radar sensor; the position of at least one traffic path is identified with the aid of an accumulation of object trajectories; the positions of barrier straight lines are ascertained with the aid of radar reflections of the closed barriers; and the danger zone is determined by linking information on the identified position of the at least one traffic path with information on the ascertained position of the barrier straight lines.