Motorcycles are vulnerable in traffic. In comparison with drivers of motorised four-wheeled vehicles, motorcyclists have a high risk of fatal or serious injury due to a crash.
The main type of conflict in which a motorcyclist is injured or killed is a collision between a motorcycle and a car or van (circa 50% of the crashes). In many cases this crash is caused by the car driver failing to yield to the motorcyclist.
In traffic literature these types of crashes have become known as “looked-but-failed-to-see” crashes, or “motorcycle conspicuity-related” crashes, because they are thought to be related to the low conspicuity of motorcycles.