A Longest-Queue-First Signal Scheduling Algorithm with Quality of Service Provisioning for an Isolated Intersection

In today\u27s fast-paced society, the need to travel using automobiles is increasingly important. Aside from the road itself, the intersection is the most basic unit of a traffic system. As such, controlling the flow of traffic through intersections in an efficient manner has become a task of the utmost importance. The signal-scheduling algorithm described in this thesis is designed for just such a task. Concepts are drawn from the field of packet switching in computer networks and are applied to the traffic control problem. The method proposed utilizes a maximal weight matching algorithm to minimize the queue sizes at each approach to the intersection. The goal is to provide lower average vehicle delay as compared to a current state-of-the-art traffic signal control method. In particular, a focus is given to providing increased levels of service to high-priority vehicle classes (such as emergency vehicles or large trucks). Because the minimization of vehicle queues forms the basis of the algorithm, it is important to establish the conditions under which the system is guaranteed to be stable (i.e. the queue sizes are finite); to this end, Lyapunov function-based analysis is provided. Using a traffic simulation environment, the proposed control method is compared to control methods currently implemented in the field. The results of the simulations show that the performance gain obtained when using the proposed method can be substantial, particularly in the case where prioritization among multiple classes of vehicles is desired

Fuzzy Logic in Traffic Engineering: A Review on Signal Control

Since 1965 when the fuzzy logic and fuzzy algebra were introduced by Lotfi Zadeh, the fuzzy theory successfully found its applications in the wide range of subject fields. This is mainly due to its ability to process various data, including vague or uncertain data, and provide results that are suitable for the decision making. This paper aims to provide comprehensive overview of literature on fuzzy control systems used for the management of the road traffic flow at road junctions. Several theoretical approaches from basic fuzzy models from the late 1970s to most recent combinations of real-time data with fuzzy inference system and genetic algorithms are mentioned and discussed throughout the paper. In most cases, fuzzy logic controllers provide considerable improvements in the efficiency of traffic junctions’ management

Fuzzy Logic in Traffic Engineering: A Review on Signal Control

Since 1965 when the fuzzy logic and fuzzy algebra were introduced by Lotfi Zadeh, the fuzzy theory successfully found its applications in the wide range of subject fields. This is mainly due to its ability to process various data, including vague or uncertain data, and provide results that are suitable for the decision making. This paper aims to provide comprehensive overview of literature on fuzzy control systems used for the management of the road traffic flow at road junctions. Several theoretical approaches from basic fuzzy models from the late 1970s to most recent combinations of real-time data with fuzzy inference system and genetic algorithms are mentioned and discussed throughout the paper. In most cases, fuzzy logic controllers provide considerable improvements in the efficiency of traffic junctions' management

Cálculo de la demora en carreteras convencionales mediante lógica fuzzy

La demora de vehículos es uno de los principales factores para determinar el nivel de servicio de una carretera convencional. La determinación de un método que permita calcularlo con fiabilidad para todos los conductores es materia de numerosos estudios, debido a la gran cantidad de factores, y a las diferencias entre conductores debido a la percepción subjetiva de estos factores. En este trabajo se ha diseñado un sistema de cálculo de demoras mediante el uso de técnicas de razonamiento aproximado a través de lógica fuzzy. De este modo se ha podido tratar adecuadamente la subjetividad de los conductores a la hora de calcular la demora independiente de cada vehículo. El sistema diseñado se divide en siete subsistemas fuzzy que calculan la calidad del entorno, el coche y el conductor, a partir de los cuales calcula el nivel de seguridad mediante otro subsistema fuzzy. Posteriormente utiliza esta información para calcular, mediante otros subsistemas fuzzy, si el espacio disponible para adelantar es suficiente, si el conductor considera posible adelantar y si desea adelantar. Finalmente se ha propuesto un nuevo sistema de clasificación de vehículos demorados que utiliza los datos de posibilidad y deseo de adelantar calculados anteriormente para determinar el estado del vehículo. Todos estos cálculos se realizan a partir de medidas externas relativas al entorno, al conductor, al coche y a la circulación. Para probar este sistema se realizaron encuestas a diferentes usuarios de carreteras convencionales y se compararon sus respuestas con las del sistema, obteniendo coincidencias en un más de un 90% de los casos. Se concluye que el nuevo enfoque fuzzy que se ha aportado al cálculo de la demora es efectivo y capaz de tratar la subjetividad que no se podía tratar con métodos tradicionales. [ABSTRACT] Car delay is one of the main factors used to calculate the level of service on rural highways. To establish a method which allows a faithful calculation for every driver is the subject of many researchs, because of the very different factors and the differences between the different subjective perceptions drivers have. In this work a system for the calculation of car delays has been developed using approximate reasoning with fuzzy logic. This way, drivers subjectivity has been managed when calculating individual car delays. The system is divided into seven fuzzy subsystems that calculate the quality of the environment, the car and the driver, and uses this qualities to calculate the level of safety using another fuzzy system. Then, this information is used to work out, by means of other fuzzy systems, if the gap available to overtake is enough, if the driver thinks he can overtake and if the driver wants to overtake. Finally a new system of clasification for delayed vehicles has been proposed. This proposed system uses the posibility and willing of overtaking data previously calculated to determine the state of the vehicle. All this calculations are made from external measurements related to car, environment, driver and traffic. Some surveys were made to several users of rural highways to test the system. Their answers were compared with system answers, being the same on a 90% of the answers. In conclusion, the new fuzzy approach given for the calculation of delay is effective, and is able to manage subjectivity, which was unable to manage with traditional methods

Computational intelligence-based traffic signal timing optimization

 Traffic congestion has explicit effects on productivity and efficiency, as well as side effects on environmental sustainability and health. Controlling traffic flows at intersections is recognized as a beneficial technique, to decrease daily travel times. This thesis applies computational intelligence to optimize traffic signals\u27 timing and reduce urban traffic