V2X Communication and Intersection Safety L. Le, A. Festag, R. Baldessari, and W. Zhang, NEC Laboratories Europe Abstract Vehicle-to-vehicle and vehicle-to-infrastructure communication (V2X communication) has great potential to increase road and passenger safety, and has been considered an important part of future Intelligent Transportation Systems (ITS). Several R&D projects around the world have been investigating various aspects of V2X communication. Some of these projects focus on specific issues of V2X communication for intersection safety (communication-based intersection safety) because intersections are the most complex driving environments where injury and fatal accidents occur frequently. In this paper, we discuss the technical details of V2X communication and discuss how it can be used to improve intersection safety. 1 Introduction In recent years, V2X communication has attained significant attention from both academia and industry because it has great potential to increase road and passenger safety. Several R&D projects around the world have been working on different aspects of V2X communication. Some of these projects have been investigating specific issues of V2X communication for intersection safety (communication-based intersection safety) because intersections are the most complex driving environments where injury and fatal accidents occur frequently. Research activities for communication-based intersection safety have been conducted in different research projects in Europe, Japan, and in the U.S. [1, 2, 3, 4]. However, many questions related to communication-based for intersection safety remain open. For example, previous work implemented proprietary solutions for communication-based intersection safety as a proof of concept but did not consider important standards currently being defined in the Car-to-Car Communication Consortium (C2C-CC) [5] and the ETSI Technical Committee for Intelligent Transport Systems (ETSI TC ITS). Further, solutions for communication-based intersection safety developed so far do not consider multi-hop forwarding, a networking technology that can provide important benefits for road safety by significantly extending a driver’s vision and increasing his reaction time. In this paper, we investigate an integrated approach for communication-based intersection safety by considering it in the big picture of V2X communication. The rest of our paper is organized as follows. We review relevant related work in Section 2. We provide the background for V2X communication in Section 3. We discuss how V2X communication can improve intersection safety in Section 4. We summarize our paper in Section 5. 2 Related Work Thanks to its importance, intersection safety has been investigated in several research projects around the world. In this section, we review a number of important activities for intersection safety in Europe, Japan, and the U.S. We pay special attention to communication-based intersection safety. 2.1 Communication-Based Intersection Safety in Europe In Europe, specific issues related to communication-based intersection safety were first addressed in the pioneering project INTERSAFE which combined sensor and communication technologies to increase intersection safety [1, 7, 8]. INTERSAFE’s goal was to develop an Intersection Assistant that can reduce or even eliminate fatal accidents at intersections. An Intersection Assistant can provide intersection safety in two main ways. First, the Intersection Assistant can help a vehicle detect others in its neighborhood by means of sensors and bidirectional wireless communication based on the IEEE 802.11p standard. When a potential collision is detected, a driver can be warned to stop for traffic from other directions. Second, a traffic light controller can also be equipped with sensors and communication devices. In this way, the traffic light controller communicates with approaching vehicles via 13th Int. Forum on Advanced Microsystems for Automotive Applications (AMAA 2009), Berlin, Germany, May 2009