Every day around the world, a large percentage of people die from traffic accident injuries. An influential indicator of survival rates after detecting the accident is the time between the occurrence of the accident and the arrival of emergency responders to the scene. Reductions in this time, in turn, may affect the numbers of fatalities, and this is achieved through using automatic traffic accident detection and notification systems which are either built-in the modern vehicles or available in the roads. This book highlights the state of arts for the existing automatic traffic accident detection and notification systems and reviews smartphone's interesting features that are motivated the researchers to develop smartphone based accident detection and notification systems, to provide an efficient solution in case the lack, complexity, cost, and the maintenance of other automatic accident detection systems. Most of the smartphone based accident detection systems rely on the high speed of the vehicle and the G-Force value to detect an accident. Hence, in addition to the high speed accident detection, this book concentrated on low speed car accident detection also.