Density Map Visualization for Overlapping Bicycle Trajectories

The trajectories of moving object include useful information on the traffic situation and user behavior. The visualization of vehicle trajectories aims to provide enhanced understanding of the given data. Recently, technological advances in the satellite tracking system and handheld device facilitated personal log tracking which shows different properties compared to the trajectories of motor-assisted vehicles. In this study, we propose a trajectory visualization method based on the density map which highlights the areas where the trajectories with different kinematic properties are intersecting each other. The proposed method divides trajectories into several groups according to the kinematic properties of the given trajectories and generates the density map for each group. Based on the density map, the intersection map which visualizes the area that the groups are intersecting was constructed. The intersection map was combined with the density map to show the influence of the intersected area. In order to evaluate proposed method, we collected the bicycle trajectories and visualized them. The results showed that our visualization method was able to provide some visual insights which is hard to be noted from previously proposed visualization methods.