On 24 November 2020, Professor Jun Xie gave a lecture on the topic of “Path-based algorithms for bi-criteria traffic assignment problems” via a video conference. Professor Tian-Liang Liu held the conference andabout 50 teachers and students of the SEM participated in the video conference and discussed the study with the speaker.
Traffic assignment is the basic method for traffic network analysis. Different from the standard traffic assignment problem, the bi-criteria traffic assignment usually considers time and money. Under the same condition of time and money, different travelers have different perceived generalized costs due to different values of time. The infinite dimensional problem depicts the travelers’ value of time as a continuous distribution. The infinite dimensional problem for bi-criteria traffic assignment can describe the travelers’ route choices more accurately under different conditions. Compared with discrete distribution, the continuous distribution of values of time provides better mathematical properties and lays a foundation for its extended application. In this problem, there is a corresponding relationship between the path flow and the path boundary division. This study develops two efficient path-based algorithms for bi-criteria traffic assignment problems from these two perspectives and the equilibrium states are gradually realized through path flow switching and the adjustment of path boundary division. At last, the algorithms are tested in different-scale networks. Sensitivity analyses are conducted for demand, monetary costs and other factors.
Professor Xie’s logical and simple explanation bringsaudiences new research enlightenment. The teachers and students had an in-depth discussion and exchange with Professor Xie on the research topic.
Dr. Jun Xie is currently an Associate Professor at Southwest Jiaotong University.Prior to joining Southwest Jiaotong University, he got his doctor’s degree at Tongji University and worked as a post doctor at Shagnhai Jiaotong University and Northwestern University, USA. Dr. Xie’s research interests include large-scale urban traffic network modeling, public transit network modeling, and optimization algorithm. In 2018, Dr. Xie won The Stella Dafermos Best Paper Award from the National Science Council Transportation Branch, USA. He has been in charge of the general project and youth project of the National Natural Science Foundation of China. He has participated in the dispatching plan of the National Post-doctoral International Exchange Program and the youth project of CFF-DIDI Gaiya foundation. Dr. Xie has published nearly 20 papers in Transportation Science, Transportation Research Part A, B, C & E and other journals in transportation field.
