La presente tesis se basa en el análisis del flujo vehicular, presente en el óvalo La Curva, ubicada en el distrito de Chorrillos, Departamento de Lima-Perú. El proyecto evalúa las condiciones de servicio, diseño del óvalo y el tráfico vehicular. Esta evaluación es realizada mediante un modelo microscópico que es simulado en el software Vissim 9.0. La construcción del modelo consiste en 4 fases. La primera, trata del análisis previo, que abarca desde la recolección de datos hasta el procesamiento en gabinete. Por un lado, la toma de medidas geométricas se realizó en un día de menor volumen vehicular. Por otro lado, el aforo vehicular y peatonal se realizó en un día típico. La segunda fase consiste en el modelamiento inicial, que busca trasladar el diseño geométrico actual al Vissim para proceder con la microsimulación. Asimismo, se realizaron múltiples corridas hasta lograr la optimización del modelo, previo precalentamiento y calibración del mismo. La tercera fase analiza el diseño propuesto en base a los parámetros de eficiencia vehicular, como son el tiempo de viaje (demoras), la longitud de cola y el nivel de servicio. La propuesta busca optimizar el sistema de semaforización, actualmente existente e inoperativa, y un cambio de nivel en una de las avenidas que concurre mayor cantidad flujo vehicular. En la última fase se busca evaluar y comparar los resultados, tanto de la situación actual como de la alternativa propuesta. Finalmente, los parámetros que presenten mejoras en su servicio serán determinantes para reducir el problema de congestión vehicular. / This thesis is based on the analysis of vehicle flow, present in the La Curva oval, located in the district of Chorrillos, Department of Lima-Peru. The project evaluates service conditions, oval design and vehicular traffic. This evaluation is done through a microscopic model that is simulated in Vissim 9.0 software. The construction of the model consists of 4 phases. The first one deals with the previous analysis, which ranges from data collection to cabinet processing. On the one hand, the geometric measurements were taken on a day with less vehicular volume. On the other hand, vehicular and pedestrian traffic was performed on a typical day. The second phase consists of the initial modeling, which seeks to transfer the current geometric design to the Vissim to proceed with the microsimulation. Likewise, multiple runs were performed until the model was optimized, after preheating and calibrating it. The third phase analyzes the proposed design based on vehicle efficiency parameters, such as travel time (delays), tail length and service level. The proposal seeks to optimize the traffic signaling system, currently existing and inoperative, and a change of level in one of the avenues that has the greatest amount of traffic flow. In the last phase, the aim is to evaluate and compare the results, both of the current situation and of the proposed alternative. Finally, the parameters that present improvements in their service will be decisive to reduce the problem of vehicular congestion. / Tesis

Intelligent transportation systems aim to provide innovative applications and services relating to traffic management and enable ease of access to information for various system users. The intent to utilize the excessive on-board resources in the transportation system, along with the latest computing resource management technology in conventional clouds, has cultivated the concept of the Vehicular Cloud. Evolved from Vehicular Networks, the vehicular cloud can be formed by vehicles autonomously, and provides a large number of applications and services that can benefit the entire transportation system, as well as drivers, passengers, and pedestrians. However, due to high traffic mobility, the vehicular cloud is built on dynamic physical resources; as a result, it experiences several inherent challenges, which increase the complexity of its implementations. Having a detailed picture of the number of vehicles, as well as their time of availability in a given region through a model, works as a critical stepping stone for enabling vehicular clouds, as well as any other system involving vehicles moving over the traffic network. The number of vehicles represents the amount of computation capabilities available in this region and the navigation time indicates the period of validity for a specific compute node. Therefore, in this thesis, we carry out a comprehensive stochastic analysis of several traffic characteristics related to the implementation of vehicular cloud inside a road segment by adopting proper traffic models. According to the analytical results, we demonstrate the feasibility of running a certain class of applications or services on the vehicular cloud, even for highly dynamic scenarios. Specifically, two kinds of traffic scenarios are modeled: free-flow traffic and queueing-up traffic. We use a macroscopic traffic model to investigate the free-flow traffic and analyze the features such as traffic density, the number of vehicles and their residence time. Also, we utilize the queueing theory to model the queueing-up traffic; the queue length and the waiting time in the queue are analyzed. The results show the boundaries on enabling vehicular cloud, allowing to determine a range of parameters for simulating vehicular clouds.

Con el transcurrir del tiempo, las transacciones vehiculares a través de la compra-venta se han vuelto más frecuentes y sencillas, a su vez segura, pues los propietarios registran estas transacciones en el Registro de Propiedad Vehicular para obtener la seguridad jurídica. A la par de este hecho, surge también la conducta preventiva de los propietarios de los vehículos que deciden comprar una Póliza de seguro vehicular para proteger su unidad frente a los riesgos que se puedan presentar. Si bien el propietario ha sido diligente en inscribir la transferencia vehicular y asegurar su unidad ante un eventual siniestro, hemos identificado, dos desventajas para el asegurado/propietario: (i) Este puede adquirir un bien sin conocer que el costo de la unidad ha sido cuantificada como cero, pues fue declarado como pérdida total por una compañía aseguradora, de lo cual no se tiene conocimiento debido a que no contamos con esa información de forma accesible, y (ii) De existir un siniestro la aseguradora rechazaría la cobertura por aplicación Cláusula de Exclusión expresa o por Declaración reticente o falsa, En el presente trabajo, proponemos como solución al problema la incorporación al Registro de Propiedad Vehicular de los Registros Públicos, la Obligación de las Aseguradoras de reportar la pérdida total del vehículo de tal forma que el registrador la pueda considerar como parte de la publicidad de las características de las unidades. / Over time, vehicle transactions through purchase and sale have become more frequent and simple, and at the same time safe, because the owners register these transactions in the Vehicle Property Registry to obtain legal security. At the same time, the preventive behavior of the owners who decide to buy a vehicle insurance policy to protect their unit against the risks. Although the owner has been diligent in registering the vehicle transfer and insuring his unit in the event of a loss, we have identified two disadvantages for the insured/owner: (i) The owner can acquire a property without knowing that the cost of the unit has been quantified as zero, since it was declared a total loss by an insurance company, of which we have no knowledge due to the fact that we do not have that information in an accessible manner, and (ii) If there is a claim, the insurance company would reject the coverage due to the application of an express Exclusion Clause or a reluctant or false statement. In the present work, we propose as a solution to the problem, the incorporation to the Registry of Vehicle Property of the Public Registries, the Obligation of the Insurers to report the total loss of the vehicle in such a way the person who registers, can consider it as part of the publicity of the characteristics of the units. / Trabajo de investigación

El presente trabajo de investigación busca mostrar una alternativa a los sistemas de control de tráfico vehicular existentes, integrando teorías y tecnologías existentes con el fin de poder desarrollar un sistema que sea más eficiente e implementable de una manera segura y confiable. En este caso se ha elegido utilizar la teoría de la Lógica Difusa para poder llevar a cabo esta investigación, ya que es un contexto que se amolda de muy buena manera con la problemática a tratar.

We study the application of network coding in periodic safety broadcasting in Vehicular Ad hoc Networks. We design a sub-layer in the application layer of the WAVE architecture. Our design uses rebroadcasting of network coded safety messages, which considerably improves the overall reliability. It also tackles the synchronized collision problem stated in the IEEE 1609.4 standard as well as congestion problem and vehicle-to-vehicle channel loss. We study how massage repetition can be used to optimize the reliability in combination with a simple congestion control algorithm. We analytically evaluate the application of network coding using a sequence of discrete phase-type distributions. Based on this model, a tight safety message loss probability upper bound is derived. Completion delay is defined as the delay that a node receives the messages of its neighbour nodes. We provide asymptotic delay analysis and prove a general and a restricted tighter asymptotic upper bound for the completion delay of random linear network coding. For some safety applications, average vehicle to vehicle reception delay is of interest. An instantly decodable network coding based on heuristics of index coding problem is proposed. Each node at each transmission opportunity tries to XOR some of its received original messages. The decision is made in a greedy manner and based on the side information provided by the feedback matrix. A distributed feedback mechanism is also introduced to piggyback the side information in the safety messages. We also construct a Tanner graph based on the feedback information and use the Belief Propagation algorithm as an efficient heuristic similar to LDPC decoding. Layered BP is shown to be an effective algorithm for our application. Lastly, we present a simple experimental framework to evaluate the performance of repetition based MAC protocols. We conduct an experiment to compare the POC-based MAC protocol with a random repetition-based MAC.

We study the application of network coding in periodic safety broadcasting in Vehicular Ad hoc Networks. We design a sub-layer in the application layer of the WAVE architecture. Our design uses rebroadcasting of network coded safety messages, which considerably improves the overall reliability. It also tackles the synchronized collision problem stated in the IEEE 1609.4 standard as well as congestion problem and vehicle-to-vehicle channel loss. We study how massage repetition can be used to optimize the reliability in combination with a simple congestion control algorithm. We analytically evaluate the application of network coding using a sequence of discrete phase-type distributions. Based on this model, a tight safety message loss probability upper bound is derived. Completion delay is defined as the delay that a node receives the messages of its neighbour nodes. We provide asymptotic delay analysis and prove a general and a restricted tighter asymptotic upper bound for the completion delay of random linear network coding. For some safety applications, average vehicle to vehicle reception delay is of interest. An instantly decodable network coding based on heuristics of index coding problem is proposed. Each node at each transmission opportunity tries to XOR some of its received original messages. The decision is made in a greedy manner and based on the side information provided by the feedback matrix. A distributed feedback mechanism is also introduced to piggyback the side information in the safety messages. We also construct a Tanner graph based on the feedback information and use the Belief Propagation algorithm as an efficient heuristic similar to LDPC decoding. Layered BP is shown to be an effective algorithm for our application. Lastly, we present a simple experimental framework to evaluate the performance of repetition based MAC protocols. We conduct an experiment to compare the POC-based MAC protocol with a random repetition-based MAC.

No description available.

IEEE 802.11 is an economical and efficient standard that has been applied to vehicular networks. However, the long handoff latency of the standard handoff scheme for IEEE 802.11 has become an important issue for seamless roaming in vehicular environments, as more handoffs may be triggered due to the higher mobility of vehicles. This thesis presents a new and fast location-based handoff scheme particularly designed for vehicular environments. With the position and movement direction of a vehicle and the locations of the surrounding APs, our protocol is able to accurately predict several possible APs that the vehicle may visit in the future and to assign these APs different priority levels. APs on higher priority levels will be first scanned. Once a response to scanning from an AP is received, the scanning process ends immediately. A blacklist scheme is also used to exclude those APs that showed no response to the scanning during previous handoffs. Thus, time spent on scanning APs is supposed to be significantly reduced. The simulation results show that the proposed scheme attains not only a lower prediction error rate, but also a lower MAC layer handoff latency, and that it has a smaller influence on jitter and throughput; moreover, these results show that the proposed scheme has a smaller total number of handoffs than other handoff schemes.

TRAFFIC congestions and accidents are major concerns in today’s transportation systems. This thesis investigates how to improve traffic throughput by reducing or eliminating bottlenecks on highways, in particular for merging situations such as intersections where a ramp leads onto the highway. In our work, cars are equipped with sensors that can measure distance to neighboring cars, and communicate their velocity and acceleration readings with one another. Sensor-enabled cars can locally exchange sensed information about the traffic and adapt their behavior much earlier than regular cars. / We propose proactive algorithms for merging different streams of sensor-enabled cars into a single stream. A proactive merging algorithm decouples the decision point from the actual merging point. Sensor-enabled cars allow us to decide where and when a car merges before it arrives at the actual merging point. This leads to a significant improvement in traffic flow as velocities can be adjusted appropriately. We compare proactive merging algorithms against the conventional priority-based merging algorithm in a controlled simulation environment. Experimental results show that proactive merging algorithms outperform the priority-based merging algorithm in terms of flow and delay. / More importantly, the imprecise information (errors in sensor measurements) is a major challenge for merging algorithms, because inaccuracies can potentially lead to unsafe merging behaviors. In this thesis, we investigate how the accuracy of sensors impacts merging algorithms, and design robust merging algorithms that tolerate sensor errors. Experimental results show that one of our proposed merging algorithms, which is based on the theory of time geography, is able to guarantee safe merging while tolerating two to four times more imprecise positioning information, and can double the road capacity and increase the traffic flow by 25%.

TRAFFIC congestions and accidents are major concerns in today’s transportation systems. This thesis investigates how to improve traffic throughput by reducing or eliminating bottlenecks on highways, in particular for merging situations such as intersections where a ramp leads onto the highway. In our work, cars are equipped with sensors that can measure distance to neighboring cars, and communicate their velocity and acceleration readings with one another. Sensor-enabled cars can locally exchange sensed information about the traffic and adapt their behavior much earlier than regular cars. / We propose proactive algorithms for merging different streams of sensor-enabled cars into a single stream. A proactive merging algorithm decouples the decision point from the actual merging point. Sensor-enabled cars allow us to decide where and when a car merges before it arrives at the actual merging point. This leads to a significant improvement in traffic flow as velocities can be adjusted appropriately. We compare proactive merging algorithms against the conventional priority-based merging algorithm in a controlled simulation environment. Experimental results show that proactive merging algorithms outperform the priority-based merging algorithm in terms of flow and delay. / More importantly, the imprecise information (errors in sensor measurements) is a major challenge for merging algorithms, because inaccuracies can potentially lead to unsafe merging behaviors. In this thesis, we investigate how the accuracy of sensors impacts merging algorithms, and design robust merging algorithms that tolerate sensor errors. Experimental results show that one of our proposed merging algorithms, which is based on the theory of time geography, is able to guarantee safe merging while tolerating two to four times more imprecise positioning information, and can double the road capacity and increase the traffic flow by 25%.