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Urban Transportation Network Design in Chaotic Conditions and Uncertainty in Travel Demand
Sharifi, Mohammad Sadra | 2010
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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 41179 (09)
- University: Sharif University of Technology
- Department: Civil Engineering
- Advisor(s): Pourzahedi, Hossein
- Abstract:
- Transportation systems are dynamic and complex systems due to the interaction between human and non-human factors. In certain circumstances, the dynamics of traffic flow causes the transportation system fail to reach equilibrium and chaos will occur. In such cases, travel times vary daily and travel time reliability decreases. Moreover, these systems are continuously exposed to incidents that cause a high degree of uncertainty. So, it is necessary to enter such dynamics and uncertainty in the decision making models, such as network design. In this study a bilevel network design problem is defined with chaos and uncertainty taken into account. At the higher level problem, the optimization framework minimizes the total day to day travel times, and at the lower level one a dynamic model is used to predict daily traffic flows. It is assumed that the origin-destination demands have normal distributions with known means and variances. Then, an Antithetic sampling procedure is employed to specify demands, which are then assigned to the network to solve the traffic assignment problem. Application of the proposed network design model is discussed for a three-link network and the Nguyen-Dupuis network, and a meta-heuristic genetic algorithm is used to solve the network design problem. The results show that the maximum investment funding may not be an appropriate solution for saving the network from chaos. Also, uncertainty in demand can lead to changes in network design results
- Keywords:
- Network Design ; Chaos Theory ; Dynamical Traffic Assignment ; Demand Uncertainty