Solución al problema de asignación del tránsito para un segmento de la red vial de Medellín a partir de datos reales

RESUMEN: Este artículo está basado en datos obtenidos en los más recientes estudios de transporte que se han realizado en el Área Metropolitana del Valle de Aburrá. (Medellín y otros 9 municipios). Estos estudios fueron la Encuesta Origen Destino (2005), análisis de las rutas de buses (2005) y el Plan Maestro de Movilidad (2006). En el artículo se explica el proceso utilizado para el desarrollo de una aplicación informática para resolver el problema determinístico de equilibrio de usuario en la red vial de Medellín. El código fue construido usando Visual Basic.NET ® y Microsoft Excel ® para la ejecución de algunas operaciones en un segmento de la red vial de Medellín. La distribución del flujo del equilibrio de usuario fue encontrada usando el algoritmo de Frank-Wolfe y fueron analizados algunos aspectos tales como número de iteraciones, patrones de convergencia, tiempo de respuesta y cambios en la demanda de viajes en la red. Los modelos de asignación del tránsito fueron analizados para las horas pico de la tarde. Se compararon los resultados de la asignación del tránsito del algoritmo desarrollado en este trabajo con los resultados de TransCAD ® para los datos del 2005 y fue encontrado que el software es un poco más rápido que el algoritmo, pero sin embargo éste último puede ser una buena herramienta para profesionales y estudiantes para la modelación de redes pequeñas.ABSTRACT: This paper is based on data obtained from most recent transportation studies done in the Metropolitan Area of Valle de Aburrá, city of Medellín and other 9 municipalities. The studies were based on an Origin/Destination Survey (2005), Analysis of bus routes (2006), and Mobility Master Plan (2006). This paper explains the process of writing a software application for a given network (Network of Medellin) that solves the deterministic user equilibrium problem. The software code was implemented in Visual Basic .NET®, supported by some operations using Microsoft Excel®, and hardcoded for a segment of the Medellin network. The user equilibrium distribution of flow was found by using the Frank-Wolfe algorithm. The applied algorithm was analyzed in some aspects such as number of iterations, convergence patterns, response time, as well as changes in network demand. The traffic assignment models were analyzed by using the algorithm during the P.M. peak hour (hour of highest traffic congestion). The analysis was compared with the results from the traffic assignment procedure using TransCAD® (well-known and used transportation demand software) for the 2005 database and it was found that the software is somewhat faster than the algorithm, but the latter could be a good tool for practitioners and students for modeling small networks

Modeling and Optimization for Transportation Systems Planning and Operations

In this paper, we focus on a number of applications of network optimization techniques to transportation systems analysis. In particular, network analysis problems, network design problems, and network management problems are discussed in some detail. The intent is to survey important application areas.*To be presented at the International Symposium on Large Engineering Systems, University of Manitoba, Winnipeg, Manitoba, Canada, August 9-12, 197

Equilibria on a congested transportation network

Bibliography: leaves 26-29.Supported in part by the Transportation Advanced Research Program of the U.S. Department of Transportation under contract. DOT-TSC-1058 Supported in part by the National Science Foundation under grant. 79-26225-ECSby Hedayat Z. Aashtiani and Thomas L. Magnanti

A Combined Trip Generation, Trip Distribution, Modal Split and Traffic Assignment Model

Revised and submitted to Transportation Science February 1985.We introduce a transportation equilibrium model that simultaneously predicts trip generation, trip distribution, modal split, and traffic assignment by algorithms that are guaranteed to converge to an equilibrium and are computationally efficient for large-scale systems. The model is formulated as an equivalent optimization problem, yet it allows realistic, flexible and behaviorally acceptable demand models

A linearization and decomposition algorithm for computing urban traffic equilibria

"This article has appeared in Proceedings, IEEE 192 Large-Scale Systems Symposium"--P.1.Includes bibliographical references (leaves 11-12).Supported in part by Dept. of Transportation DOT-TSC-1058. Supported in part by National Science Foundation 79-26225-ECS.by Hedayat Z. Aashtiani and Thomas L. Magnanti

Reduced gradient algorithm for user equilibrium traffic assignment problem

A path-based algorithm is developed for the static traffic assignment problem (TAP). In each iteration, it decomposes the problem into origin-destination (OD) pairs and solves each subproblem separately using the Wolfe reduced gradient (RG) method. This method reduces the dimensions of each single-OD subproblem by selecting a basic path between the OD pair and reformulating the subproblem in terms of the nonbasic paths. A column generation technique is included to avoid path enumeration in large scale networks. Also, some speed-up techniques are designed to improve the computational efficiency. The algorithm shifts flows from costlier paths to cheaper paths; however, the amount of flow shifted from a costlier path is proportional to not only the travel time but also the flow on the path. It is applied to the Philadelphia and Chicago test problems, while different strategies for choosing the basic paths are examined. The RG algorithm shows an excellent convergence to relative gaps of the order of 1.0E-14 when compared against several reference TAP algorithms

A Review of Models of Urban Traffic Networks (With Particular reference to the Requirements for Modelling Dynamic Route Guidance Systems)

This paper reviews a number of existing models of urban traffic networks developed in Europe and North America. The primary intention is to evaluate the various models with regard to their suitability to simulate traffic conditions and driver behavior when a dynamic route guidance system is in operation

Steady state minimization of traveler cost for freeway corridor systems

Bibliography: leaves 47-52.Prepared under grant DOT/TSC 849. Originally presented as the author's thesis, (B.S.) in the M.I.T. Dept. of Electrical Engineering and Computer Science, 1976.by Michael B. McIllrath

Modelagem analítica de alocação de tráfego para avaliação de alternativas de uso do eixo norte-sul de Curitiba

TCC (graduação) - Universidade Federal de Santa Catarina. Campus Joinville. Engenharia de Transportes e Logística.A cidade de Curitiba foi pioneira na implantação do sistema BRT e, graças ao sucesso do sistema, obteve reconhecimento internacional em planejamento urbano e de transportes. Atualmente, o sistema de transporte público da cidade transporta mais de 1,5 milhões de passageiros por dia útil. Porém, a grande procura por este serviço tem aproximado algumas linhas do BRT à saturação. Neste sentido, surgiu o projeto do primeiro metrô da cidade em substituição à linha mais carregada, o eixo norte-sul. Uma das vantagens do projeto é que a maior parte do metrô será subterrâneo e passará abaixo das canaletas exclusivas de ônibus. É esperado que os atuais usuários do BRT migrem para o novo sistema e, além disso, os motoristas de veículos particulares também sejam atraídos. Com a desativação desta linha do BRT, surge a necessidade de requalificação do solo urbano local, já que este espaço ficaria ocioso. Este trabalho tem como objetivo analisar alternativas de utilização deste espaço, considerando a abertura ao fluxo de veículos em diferentes sentidos. Com os dados de contagens de tráfego obtidos em quatro bairros da região de estudo, a matriz origem-destino de viagens foi estimada. Além disso, informações sobre a rede viária foram também extraídas. Assim, quatro cenários foram modelados para alocar o fluxo de viagens na rede utilizando abordagem analítica de equilíbrio do usuário. Para isso, o algoritmo de Frank-Wolfe foi implementado na linguagem de programação C/C++. Os resultados de todos os cenários foram comparados através do indicador de tempo médio de viagem. Dessa forma, analisou-se se a abertura ao tráfego de veículos comuns reduz significamente este indicador.The city of Curitiba pioneered the implementation of the BRT system and due to the success of the system obtained international recognition in urban and transportation planning. Currently, the city's public transportation system carries more than 1.5 million passengers per day. However, a high demand for this service has brought some BRT lines close to saturation. In this sense, the project of the first subway of the city appeared in substitution of the loaded line, the north-south axis. One of the advantages of the project is that most of the subway will be underground and will pass beneath the exclusive bus lanes. The current BRT users are expected to migrate to the new system and in addition individual vehicle drivers will also be attracted. With the deactivation of this BRT line, the need for qualification of the local urban land arises, since this space would be idle. This work aims to analyze alternatives of use of this space, considering the opening to the flow of vehicles in different directions. With the traffic counts data obtained in four neighborhoods of the study region, the origin-destination trip matrix was estimated. In addition, information about the road network was also extracted. Thus, four scenarios were modeled to assign the trip flow in the network using user equilibrium analytical approach. For this purpose, the Frank-Wolfe algorithm was implemented in C/C++ programming language. The results of all scenarios were compared using the average travel time indicator. In this way, it was analyzed whether the opening to common vehicle traffic significantly reduces this indicator