Research Interests

  • Jamming Phenomena in Traffic Flow
    Various kinds of jamming phenomena are observed in our daily life. In particular, a traffic jam on a motorway is a very familiar phenomenon and attracts a lot of researchers due to its possibility of new insights into collective dynamics of interacting particles. Various mathematical models for traffic flow have been proposed in the last few decades. Some of them are focused on the behavior of individual particles, i.e., microscopic approach. In contrast, the dynamics are sometimes described by a compressible fluid model based on the macro-scale mean density and mean velocity, i.e., macroscopic approach.
    One of my interests is to explain analytically the relation between macroscopic and microscopic models, which describe the same phenomena.
    Jamming Phenomena in Traffic Flow : Flash Movie (In Japanese)
    Cellular Automaton Modeling for Traffic Flow : Flash Movie (In Japanese)
  • Illusion Phenomena in Perception of Drivers
    Traffic congestions occurs near a sag section on a motorway. Since the gradient of a road changes gradually and imperceptibly in a sag section, drivers can not notice it and sometimes they even perceive it as a counter-gradient. Thus, it becomes difficult for drivers to keep their appropriate velocity and eventually traffic congestions are occurred due to the fluctuation of the veolocity.
    One of my interests is to notice the gradient of a road in a sag section precisely to alleviate the traffic congestions, by analyzing the phenomena of visual illusion.
    Mistery Road (Yashima, Kagawa, Japan) : Flash Movie
    These mathematical challenges for alleviating traffic congestions make a big contribution to reduce the environmental burden and economic losses in our society.

    Research Achievements

    Recent Work

  • "Car-following model with relative-velocity effect and its experimental verification"
    Daisuke Shamoto, Akiyasu Tomoeda, Ryosuke Nishi and Katsuhiro Nishinari,
    Physical review E., Vol.83 No.4, 046105 (2011).
    In driving a vehicle, drivers respond to the changes of both the headway and the relative velocity to the vehicle in front. In this paper a new car-following model including these maneuvers is proposed. The acceleration of the model becomes infinite (has a singularity) when the distance between two vehicles is zero, and the asymmetry between the acceleration and the deceleration is incorporated in a nonlinear way. The model is simple but contains enough features of driving for reproducing real vehicle traffic. From the linear stability analysis, we confirm that the model shows the metastable homogeneous flow around the critical density, beyond which a traffic jam emerges. Moreover, we perform experiments to verify this model. From the data it is shown that the acceleration of a vehicle has a positive correlation with the relative velocity.
  • Other Works

  • Previous papers and proceedings (in English)
  • Presentations
  • Articles

  • Vitae

    Academic Degree

    Job History

    Member of Japanese Conferences



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