The invention relates to methods and vehicle-to-vehicle communication systems for determining a gap in traffic between two vehicles for a lane change of a vehicle. A method comprises the identification (110) of the gap in traffic on the basis of a first detection step and on the basis of a second detection step. The first detection step is based on at least one vehicle-to-vehicle status message of at least one other vehicle (200). The second detection step is based on an on-board sensor system of the vehicle (100).