Towards a distributed and infrastructureless vehicular traffic management system Abstract   In the past few years, several systems have been proposed to deal with issues related to the vehicular traffic management. Usually, their solutions include the integration of computational technologies such as vehicular networks, central servers, and roadside units. Most systems use a hybrid approach, which means they still need a central entity (central server or roadside unit) and Internet connection to find out an enroute event as well as alternative routes for vehicles. It is easy to understand the need for a central entity because selecting the most appropriate vehicle to perform aforementioned procedures is a difficult task. This is especially true in a highly dynamic network. In addition to that, as far as we know, there are very few systems that apply the altruistic approach (not selfish behavior) to routing decisions. Because of that, the issue addressed in this work is how to perform the vehicular traffic management, when an enroute event is detected, in a distributed, scalable, and costeffective fashion. To deal with these issues, we proposed a distributed vehicle traffic management system, named as dEASYxc2xa0(distributed vEhicle trAffic management SYstem). The dEASY system was designed and implemented on a threelayer architecture, namely environment sensing and vehicle ranking, knowledge generation and distribution, and knowledge consumption. Each layer of the dEASY architecture is responsible for dealing with the main issues that were not addressed in related works or could be improved. The threelayer architecture is arranged as follows: the first layer deals with the task of selecting the most appropriate vehicle to perform data forwarding andor knowledge generation, the second one addresses the knowledge generation and distribution, and the third layer applies an altruistic approach to choose an alternative route. Simulation results have shown that, compared with other systems from the literature, our proposed system has lower network overhead due to applied vehicle selection and broadcast suppression mechanisms. On average, dEASY also outperformed all other competitors in what regards to the travel time and time lost metrics. Through the analysis of results, it is possible to conclude that our infrastructureless system is scalable and costeffective.

DisTraC: A Distributed and LowOverhead Protocol for Traffic Congestion Control Using Vehicular Networks The increase in traffic congestion in big cities causes negative impacts on several areas, such as health and the economy. One of the main alternatives to reduce traffic jams are Intelligent Transportation Systems (ITS) that use technologies such as inductive loops, Global Positioning System (GPS), and wireless communication. The vehicular networks enable the wireless communication in the vehicular environment. This communication may occur from Vehicle to Vehicle (V2V) or from Vehicle to Infrastructure (V2I). However, the installation and maintenance of the infrastructures necessary to cover urban areas may have high costs. Therefore, this work presents a new Distributed and lowoverhead protocol for Traffic Congestion control (DisTraC) based on V2V communication. The protocol aims to reduce the average travel time of vehicles ensuring a low communication overhead. Simulations results shown that DisTraC outperforms other studies found in the literature in terms of communication overhead and is more efficient in reducing traffic congestion.