Active safety is an important feature of a modern vehicle to provide precaution warning or compensatory control before the pre-crash stage of vehicle safety. All vehicle signals and information are acquired by several in-vehicle sensors on ECUs or surrounding vehicles, and integrated in vehicle gateway through in-vehicle or vehicle-to-vehicle communications. The information exchanged among the host and surrounding vehicles provides comprehensive vehicle and driving status of each vehicle, so the driver can drive more safely with the cooperative driving mechanism. The demonstration system consists of a vehicle gateway, which is based on a heterogeneous multi-core processor, consisting of one ARM core for I/O control and system management and two DSP cores for intensive computation of information fusion. After reaching within the communication limit, the vehicles set up time synchronization and then exchange vehicle information. The acquired sensor data and received vehicle information are time aligned and fed into PAC DSPs for information fusion, which consists of four phases, signal processing, location mapping, trajectory prediction and risk assessment. The risk assessment evaluates the probability of car crash and broadcast the warning message to its surrounding vehicles, if the risk level is raised beyond a threshold. The cooperative driving is fulfilled by sharing the vehicle information and emergency warning through wireless communication, so a driver can be aware of the dangerous situation and also be suggested an adequate response earlier.