Showing papers on "Vehicular communication systems published in 2008"

A tutorial survey on vehicular ad hoc networks

Abstract: There has been significant interest and progress in the field of vehicular ad hoc networks over the last several years. VANETs comprise vehicle-to-vehicle and vehicle-to-infrastructure communications based on wireless local area network technologies. The distinctive set of candidate applications (e.g., collision warning and local traffic information for drivers), resources (licensed spectrum, rechargeable power source), and the environment (e.g., vehicular traffic flow patterns, privacy concerns) make the VANET a unique area of wireless communication. This article gives an overview of the field, providing motivations, challenges, and a snapshot of proposed solutions.

Secure vehicular communication systems: design and architecture

Abstract: Significant developments have taken place over the past few years in the area of vehicular communication systems. Now, it is well understood in the community that security and protection of private user information are a prerequisite for the deployment of the technology. This is so precisely because the benefits of VC systems, with the mission to enhance transportation safety and efficiency, are at stake. Without the integration of strong and practical security and privacy enhancing mechanisms, VC systems can be disrupted or disabled, even by relatively unsophisticated attackers. We address this problem within the SeVeCom project, having developed a security architecture that provides a comprehensive and practical solution. We present our results in a set of two articles in this issue. In this first one, we analyze threats and types of adversaries, identify security and privacy requirements, and present a spectrum of mechanisms to secure VC systems. We provide a solution that can be quickly adopted and deployed. In the second article we present our progress toward the implementation of our architecture and results on the performance of the secure VC system, along with a discussion of upcoming research challenges and our related current results.

Secure vehicular communication systems: implementation, performance, and research challenges

Abstract: Vehicular communication systems are on the verge of practical deployment. Nonetheless, their security and privacy protection is one of the problems that have been addressed only recently. In order to show the feasibility of secure VC, certain implementations are required. we discuss the design of a VC security system that has emerged as a result of the European SeVe-Com project. In this second article we discuss various issues related to the implementation and deployment aspects of secure VC systems. Moreover, we provide an outlook on open security research issues that will arise as VC systems develop from today's simple prototypes to full-fledged systems.

Evaluation of the IEEE 802.11p MAC Method for Vehicle-to-Vehicle Communication

Abstract: In this paper the medium access control (MAC) method of the upcoming vehicular communication standard IEEE 802.11p has been simulated in a highway scenario with periodic broadcast of time-critical packets (so-called heartbeat messages) in a vehicle-to-vehicle situation. The 802.11p MAC method is based on carrier sense multiple access (CSMA) where nodes listen to the wireless channel before sending. If the channel is busy, the node must defer its access and during high utilization periods this could lead to unbounded delays. This well-known property of CSMA is undesirable for time-critical communications. The simulation results reveal that a specific node/vehicle is forced to drop over 80% of its heartbeat messages because no channel access was possible before the next message was generated. To overcome this problem, we propose to use self-organizing time division multiple access (STDMA) for real-time data traffic between vehicles. This MAC method is already successfully applied in commercial surveillance applications for ships (AIS) and airplanes (VDL mode 4). Our initial results indicate that STDMA outperforms CSMA for time-critical traffic safety applications in ad hoc vehicular networks.

Certificate Revocation List Distribution in Vehicular Communication Systems : EPFL Technical Report, LCA-REPORT-2008-019

Abstract: Certificate Revocation List Distribution in Vehicular Communication Systems : EPFL Technical Report, LCA-REPORT-2008-019

Certificate revocation list distribution in vehicular communication systems

Abstract: The need to evict compromised, faulty, or illegitimate nodes is well understood in prominent projects designing security architectures for Vehicular Communication (VC) systems. The basic approach envisioned to achieve this is via distribution of Certificate Revocation Lists (CRLs). Nonetheless, the problem of how to distribute CRLs effectively and efficiently has not been investigated. In this paper, we addresses exactly this problem. We propose a flexible, simple, and scalable design that leverages on road-side VC infrastructure. Our scheme can distribute large CRLs across wide VC regions within minutes, by utilizing a bandwidth of only a few Kbps at each road-side infrastructure unit.

Research on Intelligent Transportation System Technologies and Applications

Abstract: ITS (intelligent transportation system) has been developed since the beginning of 1970s, which makes human, vehicles, roads united and harmonic and establishes a wider range, fully efficient, real-time and accurate information manage system. In the paper, intelligent transportation technologies such as wireless communications, computational technologies, and Sensing technologies have been proposed. Intelligent transportation applications are also introduced. This is a belief abstract for an invited talk at the workshop on power Electronics and Intelligent transportation system.

Measuring the performance of IEEE 802.11p using ns-2 simulator for vehicular networks

Abstract: The 802.11p protocol, also known as wireless access for the vehicular environment (WAVE), has recently gained momentum in the area of research and development. The WAVE protocol provides enhancements to the physical (PHY) and medium access control (MAC) layers of the existing 802.11 wireless standards. These enhancements are required to support the intelligent transportation systems (ITS) initiatives of the US Department of Transportation regarding vehicle-to-vehicle, vehicle-to-infrastructure, and infrastructure-to-vehicle communication. Many research groups have contributed to the development of the protocol. Many of the same individuals have worked to extend the ns-2 network simulator to correctly simulate wireless mobile networking, specifically vehicle adhoc networks (VANETs). The objective of this research project is to measure the performance of the WAVE protocol at the MAC layer, using the ns-2 simulator. Specifically, the simulations measure aggregate throughput, average delay, and packet loss metrics.

A Simple Analytical Model for the Periodic Broadcasting in Vehicular Ad-Hoc Networks

Abstract: Nowadays in Europe, USA, Japan and other countries many efforts are being made towards the development and ubiquitous deployment of active vehicular safety systems, which are based on car-to-car and car-to-infrastructure communications. International standard IEEE 802.11p defines low layers protocols for vehicular networks aimed to support Intelligent Transportation Systems (ITS) applications. Periodic broadcasting of short status messages (beacons) is foreseen as one of the key modes, which should be efficiently handled to provide active safety in vehicular networks. This paper presents a simple analytical method to compute the probability of successful message reception and mean message transmission delay in IEEE 802.11p vehicular ad-hoc network with periodic broadcasting of messages. We investigate the influence of beaconing period on the above performance metrics.

Routing in Vehicular Networks: Feasibility, Modeling, and Security

Abstract: Vehicular networks are sets of surface transportation systems that have the ability to communicate with each other. There are several possible network architectures to organize their in-vehicle computing systems. Potential schemes may include vehicle-to-vehicle ad hoc networks, wired backbone with wireless last hops, or hybrid architectures using vehicle-to-vehicle communications to augment roadside communication infrastructures. Some special properties of these networks, such as high mobility, network partitioning, and constrained topology, differentiate them from other types of wireless networks. We provide an in-depth discussion on the important studies related to architectural design and routing for such networks. Moreover, we discuss the major security concerns appearing in vehicular networks.

Characterizing Multi-Hop Communication in Vehicular Networks

Abstract: Majority of characterization studies on Vehicular Networks are based on simulations that assume little network errors and consistent signal strength. Existing VANET experiments, on the other hand, focus mostly on single-hop communication. In this paper, we present the results of an extensive measurement campaign involving up to six vehicles and evaluating the performance of IEEE 802.11 in different vehicular communication scenarios: vehicle-to-vehicle (V2V) and infrastructure-to-vehicle (I2V). We concentrate our evaluation on multi-hop communication in these two scenarios. We found that distance and line of sight communication are the two main factors affecting the multi-hop inter-vehicle communication. The experimental results confirm also the feasibility of using ad hoc networks to extend the transmission range of the infrastructure and the connection time for cars in motion.

IP address configuration in VANET using centralized DHCP

Abstract: Vehicular ad-hoc networks (VANET) are a mobile adhoc networking technology to facilitate vehicle-to-vehicle and vehicle-to-roadside communication. A vehicle in VANET is considered to be an intelligent mobile node capable of communicating with its neighbors and other vehicles in the network. As in a mobile ad-hoc network (MANET) it is necessary to identify or address each vehicle in the vehicular ad-hoc network with a unique address. The current addressing mechanisms in VANET do not succeed in configuring the vehicle with a unique address. Furthermore, there is a need for address reconfigurations depending on the mobility patterns. In order to deal with these problems, we have presented a centralized addressing scheme for VANET using DHCP (Dynamic Host Configuration Protocol). Results obtained in our approach are compared against the results presented in one of the existing addressing mechanism in VANET. It is observed that our approach is efficient and feasible for vehicular ad-hoc networks.

TrafficGather: An Efficient and Scalable Data Collection Protocol for Vehicular Ad Hoc Networks

Abstract: Nowadays, vehicles have become an indispensable part of modern life. To ensure road safety and to make possible dynamic route scheduling, emergency message dissemination, traffic monitoring, and so forth, it is desirable to develop a common protocol for inter-vehicle communications (IVC) in order to realize intelligent transportation systems (ITS). Accordingly, this study proposes a protocol, designated as TrafficGather, based on a cluster networking technique. The protocol subdivides a road section into a series of "road blocks", each covered by a network cluster, and permits a vehicle within a road block to transmit its traffic information only in a specific time slot. Simulations performed using the Qualnet simulator confirm the effectiveness and efficiency of the proposed protocol.

“On the Road” - Reflections on the security of Vehicular communication systems

Abstract: Vehicular communication (VC) systems have recently drawn the attention of industry, authorities, and academia. A consensus on the need to secure VC systems and protect the privacy of their users led to concerted efforts to design security architectures. Interestingly, the results different project contributed thus far bear extensive similarities in terms of objectives and mechanisms. As a result, this appears to be an auspicious time for setting the corner-stone of trustworthy VC systems. Nonetheless, there is a considerable distance to cover till their deployment. This paper ponders on the road ahead. First, it presents a distillation of the state of the art, covering the perceived threat model, security requirements, and basic secure VC system components. Then, it dissects predominant assumptions and design choices and considers alternatives. Under the prism of what is necessary to render secure VC systems practical, and given possible non-technical influences, the paper attempts to chart the landscape towards the deployment of secure VC systems.

A Vehicle Collision Warning System Employing Vehicle-To-Infrastructure Communications

Abstract: Road safety has become an important issue and gained much attention for many years. To avoid vehicle collisions on the roads, researchers have proposed various collision warning systems (CWS) using different technologies. Compared with CWS using other technologies, a radio-based CWS is more capable of avoiding collisions in off-sight scenarios (such as the four corners of an intersection). Most existing radio-based CWSs operate using vehicle-to-vehicle communications. However, in such CWSs, high mobility of moving vehicles easily results in message collisions and link breakage, impairing the reliability of these CWSs. An alternative is employing vehicle-to-infrastructure communication to build CWSs. In this paper, we propose a radio-based CWS employing vehicle-to-infrastructure communications. Our simulation results show that the proposed CWS can effectively reduce the number of vehicle collisions without degrading the traffic throughput of a road network.

Providing over-the-horizon awareness to driver support systems by means of multi-hop ad hoc vehicle -to-vehicle communication

Abstract: The application of Driver Support Systems (DSS) is an emerging trend in the automotive industry. Advances in technology enable faster, smaller and more versatile hard- and software systems while consumers demand safer and more e�cient cars. A DSS aims to meet the consumer's demand with technologically feasible solutions. The Ph.D. Thesis \Driver Support in Congestion" by C.J.G. van Driel proposes a suite of Driver Support Systems called the Congestion Assistant. The Congestion Assistant functions by means of over-the-horizon awareness to aid the driver in traversing traffic congestion on highways. Subsystems are proposed to aid the driver and supply the driver with information. The Congestion Assistant has been tested at a functional level, but an information dissemination system was not presented in the study. In the design information was assumed to be instantaneously and reliably available. A DSS, which relies on over-the-horizon awareness in a mobile environment, poses some interesting demands on the communication system designed to distribute this information. For instance, latency must be minimal in order to guarantee freshness of information, even if it has travelled several kilometers along the road. This thesis covers the design of a communication system aimed to provide the over-thehorizon awareness to the Congestion Assistant.

Simulation-Based Performance Evaluation of Enhanced Broadcast Schemes for IEEE 802.11-Based Vehicular Networks

Abstract: Car-to-car communication (C2CC) enables cars to exchange information that can be used to, e.g., improve the drivers' safety or comfort. Recently, WLANs based on the IEEE 802.11 family of standards have been identified as promising communication technology for C2CC. Often, the information exchange between vehicles is of interest for all nearby vehicles so that the communication should be broadcast-based. However, such use cases have not been considered when the IEEE 802.11 systems have been initially designed and a significant scalability problem exists in broadcast scenarios. We present the reasons for this problem and propose several algorithms for dynamic protocol parameter adaptations. Our simulation-based evaluation shows that the suggested enhancements clearly improve the scalability of IEEE 802.11-based systems in vehicular scenarios without changing the main protocol characteristics.

An empirical study to analyze the feasibility of WIFI for VANETs

Abstract: Vehicular ad hoc networks (VANETs) are the relevant form of ubiquitous computing. Several protocols are being developed for V2R (vehicle to road side) and V2V (vehicle to vehicle) communication and the notion of intelligent vehicles is nurturing very rapidly. We have tested the existing WIFI protocol for V2V communication especially at high speed. We have proved, with the help of real life experiments and analytical justification, that WIFI is a successful means of communication between vehicles even at very high speed (i.e. 120 mph relative). Furthermore, several useful and novel applications (like parking, tourist information center, congestion control, advertisement campaign, shortest route, weather reporting, file sharing and on-board gaming) are suggested.

The Design of a Wireless Access for Vehicular Environment (WAVE) Prototype for Intelligent Transportation System (ITS) and Vehicular Infrastructure Integration (VII)

Abstract: Inspired by the overwhelming popularity of nowadays wireless local area networks (wireless LAN, or Wi-Fi), researchers and developers have uncovered their wide application perspectives in a vehicular environment. Currently, several prototypes of dedicated short range communications (DSRC) for vehicular networks have been developed by some companies for both intelligent transportation systems (ITS) and vehicular infrastructure integration (VII). However, most of the designers simply apply the existing indoor wireless technologies, such as Wi-Fi, into a vehicular environment without redesigning them for a vehicular environment. The vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) channels feature with doubly selective fading due to the high mobility of vehicles. Both theoretical analysis and experiments have verified that the indoor wireless technologies are unable to achieve optimized and robust performance when applied to a vehicular environment. Industry is calling for new physical and MAC layer protocols for ITS and VII. The IEEE 802.11p workgroup is currently working on standardizing the wireless access for vehicular environment (WAVE), which is anticipated to be ratified in 2009. In this paper, we brief the design of a WAVE prototype based on the IEEE 802.11p protocol, which allows us to implement and evaluate the performance of the IEEE 802.11p standard in a practical approach.

Experimental demonstration of the viability of IEEE 802.11b based inter-vehicle communications

Abstract: This paper demonstrates experimentally the viability of the wireless technology IEEE 802.11b for inter-vehicle communications. Although IEEE802.11b was designed for low-mobility, indoor scenarios, we demonstrate that is possible to use it in high-mobility, outdoor scenarios where vehicles reach relative speeds of 260 km/h. For the first time, this demonstration takes into account both the speed and the presence/absence of line-of-sight in the IEEE 802.11b communication link. These are key aspects to the most aggressive vehicular scenarios for VANET communications, such as urban streets where the surrounding buildings produce constant signal reflections or high-speed freeways. The results obtained are part of the Virtual Sub-Centre developed in the European COM2REACT project, which is a novel building block to manage efficiently moving groups of vehicles in close proximity.

ZigBee for Intelligent Transport System applications

Abstract: Wireless communication technologies are expected to be widely employed in the near future in Intelligent Transport System applications. The important innovations in wireless and digital electronics will support many applications in the areas of safety, environmental and emissions control, driving assistance, diagnostics and maintenance in the transport domain. It is evident that wireless communication technologies can be used in-vehicle, inter-vehicle and between vehicle and infrastructure in transport applications. Among the different possibilities, Bluetooth is currently the most widely used automotive wireless technology for in-vehicle communication while Wi-Fi is used for vehicle to vehicle communication by several pilot research projects. ZigBee also has a role, mainly in the interconnection of wireless sensor with vehicles and infrastructure. The Embedded Middleware in Mobility Applications project (EMMA) is funded under the Information Society Technologies (IST) Priority of the 6th Framework Programme of the European Commission. Intelligent Transport System applications will be taken as a pilot example where EMMA will foster cost-efficient ambient intelligence systems with optimal performance, high confidence and faster deployment. It is necessary to find suitable communication technologies to integrate heterogeneous devices such as sensors inside the vehicle level up to motes belonging to the infrastructure. The paper will focus on our experience of using ZigBee protocol for the infrastructure and vehicle sensor network in the EMMA project. Mainly, how communication between the vehicle (highly mobile) and the infrastructure can be handled using ZigBee as the most suitable communication technology in the EMMA project validation applications.

Dual Receiver Communication System for DSRC

Abstract: This is the first study and field test analysis for DSRC (Dedicated Short distance Radio System) Vehicle wireless communication system design with first prototype developed WAVE (Wireless Access in Vehicle Environment) system platform in which IEEE802.11p and IEEE1609 standard software have been implemented. In the field test, packet reach ability as one of parameter for system evaluation has been measured for both WAVE announce frame and IP packet data between On-Board-Unit (OBU) and Road-Side-Unit (RSU). After basic WAVE functional test, it has been considered about safety application with this new DSRC technology and it is also evaluated in the field testing for informing road singe and camera steaming information transmission to vehicle. In this field testing, it is compared between single receiver concept in IEEE802.11p and dual receiver concept in Car to Car Communication Consortium (C2C-CC). Under the current existing IEEE802.11p specification, there are two types of communication channels i.e. Control Channel (CCH) and Service Channel (SCH). Those channels are sending during each 50 msec interval. The CCH is used for emergency information transmission basically and SHC is used for non- critical information such as video transmission for customer usage. Therefore it should be considered about time critical for sending CCH information. So it has been measured timing for each CCH and SCH frame arrival from RSU to OBU in real field testing as basic WAVE system functions.

Experimental evaluation of a novel vehicular communication paradigm based on cellular networks

Abstract: In the field of vehicular networks, the amount of telematic services which are usually taken into account is very limited. Safety services, and specifically collision avoidance applications, practically receive an exclusive attention. Due to vehicular ad-hoc networks (VANETs) are the most used communication technology, services conceived for the vehicle domain are frequently designed to take advantage of its benefits, but also to suffer its limitations. The intention of this paper is proposing a novel communication paradigm open to the development of any vehicular service with connectivity requirements. This way, not only vehicle to vehicle (V2V) necessities are considered, but also vehicle to infrastructure (V2I) connections are taken into account with the same importance. The work presented here chooses the cellular networks as a valid alternative to VANET approaches in most of the cases, with the added value of V2I capabilities. A design based on peer to peer (P2P) networks has been implemented and tested over a real environment. The hardware/software prototype is explained and main performance measurements prove our system is a feasible communication paradigm for most of vehicular services.

Report on the "Secure Vehicular Communications: Results and Challenges Ahead" Workshop

Abstract: This is a report and a collection of abstracts from the Feb. 2008 Lausanne Workshop on Secure Vehicular Communication Systems.

A real-time road traffic information system based on a peer-to-peer approach

Abstract: Conventional traffic information systems based on client-server approaches allow car drivers to navigate real-time road traffics, but the cost for maintaining the centralized traffic centers is high. On the other hand, decentralized traffic information systems that traffic conditions are exchanged between vehicles via inter-vehicle communication (IVC) significantly reduce the construction cost and efforts. Unfortunately, while the penetration of vehicles with such the system is insufficient, the systems suffer from problems to disseminate traffic conditions in disconnected vehicular ad-hoc networks. Therefore, we propose a novel road traffic information system which utilizes both IVC and infrastructure-based peer-to-peer communications. The system is organized as a two-tier hierarchical architecture where all vehicles broadcast traffic conditions over lower-tier vehicular ad-hoc networks. Moreover, parts of vehicles with infrastructure communication facilities further form a high-tier peer-to-peer overlay and exchange traffic information and lookups to redeem the dis-connectivity of the vehicular ad-hoc networks. Simulation results demonstrate that the proposed system performs well in terms of both delay for traffic information lookup and message exchanging overheads.

Report on the "secure vehicular communications: results and challenges ahead" workshop

Abstract: The Workshop on Secure Vehicular Communications: Results and Challenges Ahead took place in February 20-21, 2008, on the EPFL campus, Lausanne, Switzerland. The event brought together experts, from a variety of organizations, working on vehicular communication systems, security and privacy. The fourteen presentations offered an overview of the latest results and reflected the views of public authorities, academia, and industry. During the one and a half days of the workshop, the thirty-five attendees had the opportunity to have an in-depth discussion on future research and development directions for vehicular communication systems security and privacy. The developments in the area of vehicular networks and communication systems, and the increasing attention from industry, academia and authorities, motivated us to organize this workshop. Vehicular communications (VC), including vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication, with the latter leading to vehicular ad hoc networks (VANETs), lie at the core of a number of research initiatives. They aim to enhance transportation safety and efficiency, with applications that provide, for example, warnings about environmental hazards (e.g., ice on the pavement), traffic and road conditions (e.g., emergency braking, congestion, or construction sites), and local (e.g., tourist) information. Nonetheless, the unique features of VC are a double-edged sword: the rich set of tools they offer make possible a formidable set of abuses and attacks. Consider any wireless-enabled device that runs a rogue version of the vehicular communication protocol stack and injects forged messages or meaningfully modifies messages transmitted by vehicle onboard communication units; or a vehicle that forges messages in order to masquerade an emergency vehicle and mislead other vehicles to slow down and yield. Furthermore, it is possible for the vehicles and their sensing, processing, and communication platforms to be compromised. Worse even, it is not difficult to consider a node could ’contaminate’ large portions of the vehicular network with false information: for example, a single vehicle can transmit false environmental hazard warnings that can then be taken up by all vehicles in both traffic streams. From a different point of view, consider a large number of wireless access points deployed across an urban area, or along a highway (at rest areas, gas stations, etc). With such a wireless infrastructure receiving transmissions from passing by vehicles, anyone that obtained access to such data could easily infer private information about the drivers and the vehicle passengers: their locations, their routes, their communications and transactions. These simple examples of abuse indicate that in all circumstances vehicular communications must be secured and the privacy of their users should be protected. It appears that the security of VC systems and the protection of their users’ privacy are indispensable. Otherwise, these systems could make anti-social and criminal behavior easier than it is today without the VC technology. If this were the case, the benefits of deploying VC systems would be in jeopardy. It is our belief that security and privacy concerns for vehicular communication systems should, and hopefully will, be addressed before the deployment of VC systems. It is our hope that this venue provided a survey of the state-of-the-art solutions, cross-pollinated research and development efforts in two continents, increased further awareness, and thus contributed towards the objective of trustworthy vehicular communication systems.

When cars start gossiping

Abstract: Vehicular ad hoc networks present challenging characteristics, such as very dynamic behavior and sparse connectivity, that need to be taken into account in designing adequate communication support. Gossip-based protocols have recently emerged as an effective approach to providing reliable and efficient communication in this domain. Nonetheless, despite the preliminary encouraging results, to the best of our knowledge, no previous work has systematically analyzed how gossip protocols are affected by the intrinsic characteristics of vehicular networks such as the very specific mobility patterns of vehicles, the relative abundance of memory and computational resources that vehicles offer, and the availability of geographical information through GPS receivers. In this paper, we aim at filling this gap by examining core requirements of vehicular network applications and analyzing the research challenges that gossip-based communication protocols need to address.

Information Dissemination and Information Assurance in Vehicular Networks: A Survey

Abstract: Vehicular networks aimed toward providing roadside services such as traffic alerts, estimated time to reach a destination, alternative routes, and in general improve the efficiency and safety on the road are emerging in both the United States and Europe. Information exchange in such networks occurs between vehicles (inter-vehicle communications) in an ad hoc manner and also with roadside base stations using so-called dedicated short range communication links. Research on technology related to vehicular networks is being conducted by many universities and is being widely reported in the mainstream media as well. Vehicular networks are thus expected to become an important part of community networks of the future. In this paper we will survey the different types of dissemination of information and the assurance of such information in vehicular networks. The paper will discuss the architecture of vehicular networks, classify different types of information exchange (safety, traffic related, and content) and different methods of information exchange (opportunistic exchange of resources between vehicles, vehicle assisted data delivery, cooperative downloading of information, etc.). Then we discuss information assurance issues in vehicular networks and survey the solutions proposed for ensuring authenticity/integrity of information, location privacy of vehicles, eviction of faulty or misbehaving vehicles from the information network (e.g., using reputation), etc.

Enhancing Automatic Incident Detection Techniques Through Vehicle To Infrastructure Communication

Abstract: One of the fundamental requirements of a traffic management system is the ability to determine when an incident has occurred so that proper responses can be initiated. Automatic incident detection (AID) has been considered a method for quickly detecting potential incidents on the road. Although vehicular ad hoc networks (VANETs) started mainly for safety applications, surprisingly a very few work have been done in VANETs for automatic incident detection while most of the research went for developing routing protocols and privacy techniques. In this paper, we introduce a novel incident detection technique for non dense traffic flow by taking advantage of communication between cars and some roadside infrastructure installed on the road every mile or so. The proposed technique can provide a great enhancement to the existing AID techniques specially under sparse traffic where most of them fail to detect non blocking incidents.