My primary research interest lies in the modeling and analysis of transport systems. Specifically, I have devoted myself to the study of the evolution of transportation networks as a research assistant in the Networks, Economics & Urban Systems (NEXUS) research group under the supervision of Dr. David Levinson since 2003.
The structural change in transportation networks has been examined by transport geographers since the 1960s. Their studies, however, were in large part limited to intuition and heuristics, due to the lack of understanding of underlying growth mechanisms. Our research models the structural growth of transportation networks while taking into consideration the interdependency of transport supply and demand and various independent initiatives that drive this process. On the one hand, we have incorporated travel demand forecasting with user equilibrium algorithm to predict traffic flows (demand) across a network in a more realistic way; on the other hand, we have adopted agent-based simulation which enables the modeling of independent economic, behavioral, regulatory, and political initiatives in a holistic process. This approach differs from the traditional optimal design practice in that it treats transport system as a complex system with incomplete information, path-dependency, and intertwined interests. In response to a widespread call for an evolutionary approach of urban transportation planning recent years, our research opens the way to study transportation systems in a dynamic context, and provides a framework in which various transportation related economic and regulatory issues can be analyzed.
The research is not limited to theoretical exploration. We have also looked into the evolution of transportation networks in several empirical cases based on historical observations. It is observed that even based on simple weakest-link or strongest-link heuristic, agent-based simulation was able to well replicate the sequence of link abandonment or addition, as well as the structural and topological attributes of the emergent networks.
My research goes beyond system modeling and analysis. With my colleagues I have examined the subjective value of time waiting at ramp meters versus that in motion using stated preference data. In China, I also had considerable experience in conducting large-scale field surveys and multi-variate statistical analyses on construction workplace management. In response to the collapse of 35W bridge in Minneapolis, Dr. Levinson and I have conducted a quick estimate of the economic loss due to this tragedy for Minnesota Department of Transportation. As part of my dissertation work, I have proposed a game-theoretic approach to examine transport infrastructure provision under alternative jurisdictional control in a dynamic framework.
Feng Xie
Researching networks & transport systems
Selected publications
Xie, F. and D. Levinson (2008). The Weakest Link: A Model of the Decline of Surface Transportation Networks. Transportation Research, part E, Vol.44E, Issue 1, p.100-113.
Levinson, D., F. Xie, and S. Zhu (2007). The Co-evolution of Land Use and Road Networks. Proceedings of the 17th International Symposium on Transportation and Traffic Theory (ISTTT).
Xie, F. and D. Levinson (2007). Jurisdictional Control and Network Growth. Networks and Spatial Economics (accepted for publication).
Xie, F. and D. Levinson (2007). Modeling the Growth of Transportation Networks: A Comprehensive Review. Networks and Spatial Economics (accepted for publication).
Xie, F. and D. Levinson (2007). Measuring the Structure of Road Networks. Geographical Analysis, Vol. 39, Issue 3, p.336-356.
Levinson, D., F. Xie, and N. Montes de Oca (2007). Forecasting and Evaluating Network Growth. Networks and Spatial Economics (accepted for publication).
Corbett, M., F. Xie, and D. Levinson. Evolution of the Second-Story City: The Minneapolis Skyway System. Environment and Planning, Part B. (under review)
Xie, F. and D. Levinson. Topological Evolution of Surface Transportation Networks. Physical Review, E. (under review)
Zhang, L., F. Xie, and D. Levinson. Variation of the subjective value of travel time under different driving conditions. Transport Policy. (under review)
Xie, F. (2007). Validation of the Model of Network Degeneration: a case study of the Indiana Interurban Network, to be presented at 54th Annual North American Meetings of the Regional Science Council (NARSC) in Savannah November 2007.