Unfortunately, the probability of death or serious injury rises with impacts at higher speeds. According to some estimates, the risk of serious injury or death doubles for every ten miles per hour over 50 miles per hour that a vehicle is traveling. As a result, pedestrians and bicyclists struck by cars driving 40 miles per hour are eight times more likely to die than a pedestrian or bicyclist struck at 20 miles per hour. A recent news report detailed a fatal car accident.