Seo Lab, Tokyo Institute of Technology

Free software


UXsim is a free, open-source macroscopic and mesoscopic network traffic flow simulator developed in Python. It is suitable for simulating large-scale (e.g., city-scale) vehicular transportation. It computes dynamic traffic flow in a network by using traffic flow models commonly utilized by transportation research. UXsim would be especially useful for scientific and educational purposes because of its simple, lightweight, and customizable features; but of course users are free to use UXsim for any purpose.

Note that UXsim is a significant expansion of the traffic flow simulator UroborosX, which is included in the book "Macroscopic Traffic Flow Simulation: Fundamental Mathematical Theory and Python Implementation" (Author: Toru Seo, Publisher: Corona Publishing Co., Ltd.).

Fig: Approximately 60,000 vehicles pass through a 10km x 10km grid network in 2 hours. Left: link state, right: vehicle trajectories

Demonstration of traffic flow

An interactive demonstration of traffic flow that is useful to learn fundamentals of it using a simulator on your web browser. You can learn traffic flow phenomena at a bottleneck, traffic state, flow-density relation, time-space diagram, vehicle trajectory, cumulative count.

Fig: Screenshot of the demo


Calibration-free traffic state estimation method using detectors and connected vehicles data. Easy-to-use for non-specialists who don't have knowledge on traffic flow theory or programming. It can be also used as Python module so that you can incorporate it into your own programs.

Fig: Visualization of input data and estimation results