Loading...

Network Design to Alleviate Chaos in the Transportation Network Flows: Cases of Deterministic and Uncertain Supply

Shahabi, Mehrdad | 2010

639 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 41177 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Pourzahedi, Hossein
  7. Abstract:
  8. Transportation networks are considered as complex systems, and in many cases they behave in such an irregular and unexpected manner. Such complexities cause problems in studying the behavior of these systems. An example of such complexities is chaos in the network flows. On the other hand, the behavior of these networks is highly affected by the incidents like accidents and bad weather. Such events affect the level of service and travel time reliability of the networks. In this research, a dynamical approach to traffic assignment has been chosen to model chaos and uncertainties in the network. By using this approach for modeling flow evolution, edge of chaos and uncertainty in supply and demand can be found. Analyzing supply in dynamical assignment models, a supply reduction parameter was introduced that can cause chaotic behavior in the network flow. Furthermore by modeling the capacity reduction in the network links, different route choice behavior of the users in the network has been shown through time series in a three-link and Nguyen-Dupuis networks. A new importance measurement for the stability of the flow in network has been introduced as the link capacity reduction. Finally, a bilevel network design problem under chaotic uncertainties, with dynamical traffic assignment as its lower level problem, has been introduced. In this design problem, a function of the mean and the variance of the daily travel times has been chosen as the objective function of the upper level problem. It has been shown that in case of network with uncertainties, it is preferred to have the investments widely spread over the network
  9. Keywords:
  10. Uncertainty ; Network Design ; Chaos Theory ; Transportation Networks ; Dynamical Traffic Assignment

 Digital Object List

 Bookmark

No TOC