The number of road accidents involving motorbikes, bicycles and other two-wheel vehicles is relatively high with respect to the total number of accidents. The reasons given are often obvious and based on the fact that a two-wheel vehicle is less stable than a four wheel one. Clearly, the passengers of, say a scooter, run greater risks than those of a car in a collision between the two, but this does not explain why the motorcycle-car collisions are more frequent in relative terms than car-car collisions. Sixty adults who had a driving license were shown a film of a car travelling along a road with heavy traffic. The adults had to tick boxes corresponding to various hazards along the road (children crossing the road, dogs freely running about etc.). The film was then showed a second time to the same adults and this time too they had to tick off the various hazards, but differently from the first film there was now a taxi that was proceeding slowly and had to be passed and a little later also a motorbike that also had to be passed. The taxi was ticked by almost all the candidates but the motorbike by only about half. Psychologists speak of lack of attention blindness to describe a situation where we do not see objects or things that are clearly in view. When one has to respond to a huge number of sensorial stimuli (visual, auditory, tactile), the brain decides to filter the weaker ones out and sometimes it screens out the wrong ones. In fact, the explanation many drivers give when they are involved in accidents with bikes or scooters etc. is: “I just did not see it”.