Visual Analytics of Trajectories with RoseTrajVis

Abstract

We propose RoseTrajVis, a visual analytics system for studying commuting behaviors using classic rose diagrams, which, given a location in a map, aggregate trajectories by direction, show additional summary information, such as average speed bands, and allow the application of spatial-temporal filters. The rose diagrams also include colored arrows on the border that point to the origin and destination of the trajectories and show the average speed. To support analytical work, the user can also adjust the aggregation radius, move a location marker to a different position on the map with automatic update of the corresponding rose diagram, and create multiple diagrams for the same location with different filters applied. We developed two prototypes of RoseTrajVis, which were evaluated through user studies covering various types of analytical tasks with trajectories. Results suggest that the concept of rose diagrams was well understood, that the system was easy to use, and reveal that most tasks were executed with no errors. RoseTrajVis provides an innovative way of aggregating trajectories and offers features that enable the analysis of commuting movements and other exploratory tasks on a map, to support urban planning and operation.