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Traffic congestion has become a great challenge and a large burden on both the governments and the citizens in vastly populated cities. The main problem, originally initiated by several factors, continues to threaten the stability of modern cities and the livelihood of its habitants. Hence, improving the control strategies that govern the traffic o...
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... each control point, the most favorable conditions are set (longer green timings and shorter red timings), in order to achieve the shortest time that the vehicle can spend in the system. Figure 4 shows the definition of the objective function inside ExtendSim Optimizer environment; where, the objective function is written in the form of an IF ELSE equation to set the soft constraints stating that maximum number of vehicles in queue must be within road capacities. The objection function states that if any of the maximum queue lengths sets are exceeded, then the maximum profit will equal the average of the sum of the best average times in system divided by their respective actual average time in system, for every given control point. ...
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The traffic wave damping problem in a circular single lane track is addressed and solved via a shared control technique which takes a model of the human drivers’ driving habits into consideration. A formal analysis shows that the effectiveness of the proposed shared controller does not depend on the parameters of the human driver’s model, which is...
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... Sistemas de tráfego são complexos, estocásticos e dinâmicos, com um comportamento que muda muito ao longo do dia, mês e ano, dificultando suas estimativas (Ezzat et al., 2014). É comum que os conflitos existentes em cruzamentos sejam controlados por semáforos, sendo este o principal motivo para a invenção dos mesmos no começo do século 20 (Wen, 2008). ...
... Neste caso, os algoritmos possuem menos tempo disponível para retornar uma solução para a semaforização, por outro lado, seus dados de entrada refletem a situação real do momento, embora isto requeira uma infraestrutura de maior custo (Zhao & Zhang, 2012;Ribeiro et al., 2016). Para Ezzat et al. (2014), as estratégias de tempo fixo podem ainda serem subdivididas em "caóticas" e "multiperiódicas"; em que aquelas consideram o dia como um todo, enquanto estas subdividem o dia em diferentes períodos, separando por exemplo, dados dos horários de pico dos demais períodos, tendendo a ser mais precisa. A revisão de Qadri et al. (2020) , : valor inteiro de 1 a 4 identificando a saída utilizada por um veículo que entrou por , cruzamento . ...
Este trabalho propõem um modelo de simulação para um conjunto de cruzamentos semaforizados de uma área localizada na região central de Uberaba-MG, com o objetivo de determinar valores para os tempos dos semáforos que permitam melhorar o fluxo de veículos. Para isto, descreve-se a dinâmica de funcionamento do sistema real, de modo a identificar as regras e comportamentos a serem incluídos no modelo de simulação, implementado via software Arena. Após a validação do modelo, realizou-se uma série de experimentos comparando diferentes cenários, incluindo experimentos fatorais; seguido por experimentos de otimização dos valores de tempo dos semáforos. O estudo de caso mostra que o tempo atual dos semáforos pode ser alterado de forma a permitir uma melhora de desempenho de até 24%; também se verifica que o Arena pode ser utilizado para a modelagem adequada de múltiplas vias, e que é possível ter uma solução prática, utilizável no mundo real.
... Hence, the main aim of this model is to design a promising congestion detection scheme that offers sensible timely warnings to the drivers about potential traffic situations and provides proper reroute recommendations accordingly. On the other hand, there are variable patterns in future traffic volumes (Ezzat et al., 2014). Therefore, an accurate data collection methodology should be planned wisely to generate a reliable estimate of traffic flows and dissipation rates as in Egypt case current population is around 101 million and Alexandria population is about 5.4 million according to Egyptian Central Agency for Public Mobilization and Statistics (CAPMAS 2020), and the total number of registered vehicles according to the last statistics available in CAPMAS in 2017 were about 9.9 million vehicles. ...
... A traffic system is a dynamic system that is distinguished by several dynamic variables. Demand outlines change from a period to another during the day (Ezzat et al., 2014). In Alexandria, the day could include five periods as shown in Table 1, which defines the rush and non-rush times. ...
Leather is a complex material mostly consisting of a matrix of collagen, chemically stabilized by various tannins. This matrix, sooner or later undergoes alterations as a consequence of interactions between their structure and environment. A comprehensive study based on multiple chemical and physico-mechanical standard tests regarding leather samples which were artificially aged from 7 to 112 days has been made at 70°C. The behavior in artificial aging of calf leather samples tanned at pilot level with two different vegetal tannins, mimosa and quebracho, were investigated due to its’s similarity to the natural degradation of historical leather samples. Physico-mechanical characteristics of historical leather can be corelated with the high impact of degree of deterioration even though there are no standard regulations. To be able to choose the proper way to achieve compatibility with an appropriate material in the restoration-conservation process, multiple sample characteristic must be known. The condition of historical leather can be assessed by a series of simple visual and physical examinations which determine the flexibility, strength and coherency of the fibers and then correlate these assessments with the condition of leather as determined by various chemical and physical-chemical analyses. Therefore, the following chemical standard tests were made: volatile substances, shrinkage temperature, extractable substances, total soluble substances and the following physico-mechanical tests: tensile strength, elongation at breaking and tear resistance.
... Hence, the main aim of this model is to design a promising congestion detection scheme that offers sensible timely warnings to the drivers about potential traffic situations and provides proper reroute recommendations accordingly. On the other hand, there are variable patterns in future traffic volumes (Ezzat et al., 2014). Therefore, an accurate data collection methodology should be planned wisely to generate a reliable estimate of traffic flows and dissipation rates as in Egypt case current population is around 101 million and Alexandria population is about 5.4 million according to Egyptian Central Agency for Public Mobilization and Statistics (CAPMAS 2020), and the total number of registered vehicles according to the last statistics available in CAPMAS in 2017 were about 9.9 million vehicles. ...
... A traffic system is a dynamic system that is distinguished by several dynamic variables. Demand outlines change from a period to another during the day (Ezzat et al., 2014). In Alexandria, the day could include five periods as shown in Table 1, which defines the rush and non-rush times. ...
The road traffic congestion has become an excessive problem and great pressure on both the governmental and social aspects especially in megacities. Hence, developing control systems that administrate the traffic flows is a vigorous solution, which can solve the problem of traffic congestion especially in megacities that should convert their services to be smart. The Intelligent Transport System (ITS) one of the Internet of Things (IoT) applications that provides a group of pioneer schemes for handling the challenges of traffic congestion. Traditionally, sensor-based structures have been used for gathering traffic information, but the coverage, cost, and real-time matters have remained unexplained, Thus, This paper aims at proposing a new model named Traffic Flow Optimization Model (TFOM) applied in Alexandria as a case study, which is considered a cost-effective and easily maintainable traffic congestion minimization method. It combines Infra-Red (IR) and active Radio Frequency Identification (RFID) technologies. TFOM is designed to minimize traffic congestion, given reroute options to the users, taken decisions regarding congestion, and finally it could be an initial step to help future predictions in linear megacities.
... The traffic system of the University of Moratuwa, Sri Lanka, was used to demonstrate and validate the proposed model. Ezzat et al. (2014) applied a simulation technique to the traffic signal timings under oversaturated conditions. A simulation model was developed, and the authors presented the actual traffic network of Alexandria, Egypt. ...
... vehicles) arrival behavior to the network. The arrival rates in this study follow the same rates in the study made by Ahmed et al [17]. Vehicles enter the system by a series of "seize" modules, then they should take a decision on which lane to use which depends on their routes. ...
Traffic congestion is one of the most significant problems in large cities, especially during peak hours. Urban traffic lights scheduling optimization plays an important role to overcome traffic jams. In this paper an empirical study was performed to minimize the average waiting time and the average queue length in two consecutive intersections by finding the optimum green/red percentages and cycle time combination. Different experiments were tested using a simulation model which has been built using ARENA software. The significant factors affecting the traffic lights performance which were studied and the best combination between them discovered using design of experiment and analysis of variance techniques. Testing the performance of different green/red percentages and cycle time was performed on the case study, and their optimal combination to reduce the congestion of the network under study was identified.
... In [19] is a suggestion for traffic management in Alexandria, Egypt (concrete and more specific data might be found in [20]). This work used collected real data, which were measured during the peaks of traffic in Alexandria. ...
The Smart City as a concept of future cities anticipates the smart and efficient traffic management. Current situation of traffic management did not offer a sufficient solution and it is not wise to use the current technology to improve the traffic situation on the city roads. This paper deals with advanced methods for optimization, the genetic algorithms, for using in urban traffic management. Implementation of genetic algorithm and also implementation of classical static solution were provided. We try to prove the advantages of modern optimization methods, which could bring more fluent traffic to the cities and solve the current challenges as i.e. high emissions, big delay, higher probability of accidents. The paper provides comparison measurements of static and dynamic solution in discrete time, discussion of the possible implementation in praxis and evaluation of the advantages and disadvantages for both methods.
... Ceylan (2013) proposed a traffic congestion minimization model in which the traffic signal setting optimization was performed through a combined simulation-optimization model i.e. differential evolutionary optimization technique with the TRANSYT traffic simulation tool and proved to be less computationally demanding than other GAs. Ezzat et al. (2014) aimed at determining a set of optimum/near-optimum signal timings to minimize the total time in the system in oversaturated conditions and their results showed that the evolutionary method for optimization excelled over single objective GA optimizer, when it came to queue lengths and vehicular waiting time (two objective functions). ...
... The system description, Period-Demand classifications, data collection and analysis procedures are thoroughly described in a previous research work [17]. Figure 2 is a graphical representation of the system under study. ...
... The near-optimum traffic signal timings generated from the GA experiment are further fed to a simulation model for validation, visualization and calculation of different response variables. Development, experimentation and validation of the simulation models are discussed in detail in [17]. The developed simulation model using Extendsim allows infinite experimentation on the model in order to evaluate the performance of the system under various signalization plans and traffic conditions. ...
Traffic Management of over-saturated urban networks is a great challenge in large metropolitan areas. Over-saturation is a severe traffic condition when excessive unbalance between the vehicular demand and the road network's capacity takes place, generating serious inflation of queuing lengths, waiting times, spillbacks and risk of accidents. Other environmental, psychological and economic aspects could also be related to the problem. However, adequate traffic management can successfully handle the demand in both space and time, and overcome the arising congestion dilemma. A mathematical model representing the traffic control stochastic environment has been developed. The optimum/near-optimum traffic signal timing values have been determined through the application of a genetic algorithm that feeds these values into a developed simulation model to obtain the corresponding queuing parameters. The generated signal timings significantly enhance the traffic performance and alleviate the choke points over a multiple-junction urban network. The developed approach has been applied on a network consisting of two consecutive junctions in Alexandria, Egypt using actual field data. Although the solution has not been implemented in reality; nevertheless, optimization results are very promising and show that the proposed model can drastically improve the queuing parameters of the vehicular flow.
