Visualizing traffic dynamics based on floating car data

The well-known spatiotemporal traffic diagram is a popular and powerful tool in the field of transportation research and practice. It is an important basis of analyzing traffic conditions, identifying bottlenecks, and controlling and routing traffic. Traditionally, the spatiotemporal diagram is constructed by using stationary detector data, and little research has focused on construction using widely existing floating car data (FCD). Therefore, this paper proposes a data-driven method to construct the spatiotemporal diagram by using FCD. The method is completely based on FCD without the aid of map-matching and geographic information system tools. Two real-world road networks in Beijing are taken as examples to demonstrate the method. The method is validated by comparing instantaneous speed contained by individual trajectories with aggregated speed in the spatiotemporal diagrams. The method helps to understand traffic dynamics from FCD, and then aids to carry out various transportation researches and applications.