The Collision Avoidance System (CAS) is nothing but a safety mechanism designed for automobile in order to decrease the accident severity. It is also recognized as a forward collision warning system, pre-crash system or collision mitigating system. This system uses the technology of radar and also sometimes laser as well as camera sensors to sense a forthcoming crash. Once the system senses the condition, based on the advancement of the system, it can either warn the driver or the system can take necessary actions. Taking the necessary actions means the CAS system can apply brakes without the driver input, steer or can do both that is applying brakes as well as steer to prevent the direct collision. By November1, 2015 all the upcoming cars will be equipped with this latest technology. At the moment, this technology is used by various car manufacturers. The manufacturer that uses this technology at the moments are Volvo, Toyota, Mercedes-Benz, BMW, Audi, Acura, Fiat, Ford, General Motors, Honda, Mazda, Nissan, Skoda, Subaru, Volkswagen, Dodge, Cadillac, Chevrolet, Infiniti, Lexus, Tesla, and SsangYong. Every manufacturer call this feature by different names such as for Volvo it is known as Collision Warning with Auto Brake (CWAB), for Volkswagen it is known as Proactive Occupant Protection, for Honda it is known as Collision Mitigation Brake System (CMBS), etc. The system used in Mazda car manufacturer is based on laser technology that can sense vehicles or any obstacles. This system is so efficient that it can cut the power of the engine as well as apply brakes. Some of the technology used by other manufacturers is so capable that they can apply brakes and also apply high tension on seatbelt's to save passengers from severe damage.