The Italian National Police started a research on vehicular traffic to improve road safety and reduce the number of theft victims. In order to support the discovery of anomalous behavior, this paper proposes a method for data analysis to automatically detect relevant hypotheses, a data mining technique to extract relevant information and a visualization technique. Traffic flow analysis is a challenging and complex task, due to the huge size of the data involved, thus falling in the realm of Big Data. Visual Analytics tools reduce and improve the search by representing a large amount of data in a small space through smart visualizations.