A method for reducing a risk of collision between a first motor vehicle, which is in particular a motorcycle, and a second motor vehicle, wherein - the first motor vehicle and the second motor vehicle travel on respectively different roads (4a, 4b) towards a common crossroads or junction of the roads (4a, 4b); and - at least one first vehicle-to-environment message is transmitted by the first motor vehicle and received by the second motor vehicle; - by a second computing unit of the second motor vehicle depending on the at least one first vehicle-to-environment message, it is determined if a risk situation exists, in which the first motor vehicle is obscured for a driver of the second motor vehicle and/or for an environmental sensor system of the second motor vehicle by a third motor vehicle preceding the first motor vehicle, a criticality analysis is performed if it has been determined that the risk situation exists, and depending on a result of the criticality analysis, a risk-reducing measure is initiated; - by an environmental sensor system of the first motor vehicle first sensor data are generated, which represent an environment lying in front of the first motor vehicle in direction of travel and the at least one first vehicle-to-environment message is generated and transmitted depending on the first sensor data, wherein the at least one first vehicle-to-environment message contains a first vehicle-to-environment sensor message concerning the first sensor data; - by a first computing unit of the first motor vehicle based on the first sensor data it is examined whether a further motor vehicle is within a preset range in front of and/or next to the first motor vehicle and the first vehicle-to-environment sensor message is transmitted only, if based on the examination it is found that the further motor vehicle is within the preset range, and/or by the second computing unit based on the at least one first vehicle-to-environment message and the first sensor data a probability for the fact that the first motor vehicle is obscured by the third motor vehicle and the criticality analysis is performed based on the probability of obscuration. - the first motor vehicle and the second motor vehicle travel on respectively different roads (4a, 4b) towards a common crossroads or junction of the roads (4a, 4b); and - at least one first vehicle-to-environment message is transmitted by the first motor vehicle and received by the second motor vehicle; - by a second computing unit of the second motor vehicle depending on the at least one first vehicle-to-environment message, it is determined if a risk situation exists, in which the first motor vehicle is obscured for a driver of the second motor vehicle and/or for an environmental sensor system of the second motor vehicle by a third motor vehicle preceding the first motor vehicle, a criticality analysis is performed if it has been determined that the risk situation exists, and depending on a result of the criticality analysis, a risk-reducing measure is initiated; - by an environmental sensor system of the first motor vehicle first sensor data are generated, which represent an environment lying in front of the first motor vehicle in direction of travel and the at least one first vehicle-to-environment message is generated and transmitted depending on the first sensor data, wherein the at least one first vehicle-to-environment message contains a first vehicle-to-environment sensor message concerning the first sensor data; - by a first computing unit of the first motor vehicle based on the first sensor data it is examined whether a further motor vehicle is within a preset range in front of and/or next to the first motor vehicle and the first vehicle-to-environment sensor message is transmitted only, if based on the examination it is found that the further motor vehicle is within the preset range, and/or by the second computing unit based on the at least one first vehicle-to-environment message and the first sensor data a probability for the fact that the first motor vehicle is obscured by the third motor vehicle and the criticality analysis is performed based on the probability of obscuration.