Abstract
Keywords: Dedicated Short Range Communications, Cooperative Intersection Collision Avoidance System, Vehicle-Infrastructure Cooperation, Ad hoc Networks.
New technologies development and implementation in automotive engineering, are continuously improving both passive and active safety systems. While passive systems reduce number of injuries and deaths on the road, active systems are expected to improve traffic flow and prevent vehicle collisions. This paper deals with the active safety systems, variety of applications and current implementation issues. Active systems include sensors, or sensor networks and communications based systems. Intelligent vehicle systems use up to fifty processors, sensors and communications to make decisions and issue warning, or take control of the vehicle. Cooperative Intersection Collision Avoidance System (CICAS), for example, is a system where vehicle and road infrastructure collaborate in order to detect hazardous situations, and avoid potential cross-path crashes at intersections. Vehicle and infrastructure systems exchange data about the state of the intersection with high reliability and low latency. CICAS uses sensors to collect information about vehicle movements near intersection, process that information in order to determine a risk of collision occurrence, and issue warnings to drivers of the vehicles in danger. These systems are good illustrations of the Dedicated Short Range Communications (DSRC) safety applications. DSRC band allocation is not standardised internationally. For example, it occupies spectrum range in the 5.9 GHz band (U.S.) or 5.8 GHz band (Europe and Japan), while the other countries have to make their own decisions. When become widely implemented, DSRC applications will enhance the safety and the productivity of the transportation systems. This article presents a review of the current state of the DSRC applications in active safety systems, and gives some guidelines and suggestions for the further advancement in its implementation.