This morning I commuted by car. The car that was ahead of me stopped because there was a large truck leaving a building. The driver of the car suddenly thought that the truck would hit her car and decided to go back without checking her rear vision mirror. End result: she crashed with me, nothing happend to my car and she got a 40 cm wide dent on the rear bumper. The accident got me thinking: what would have happened if I have been ridding my bike?