In the framework of intelligent traffic surveillance, we propose a system for efficiently storing and retrieving moving objects' trajectories extracted from surveillance cameras. We index spatio-temporal data by using a method based on off-the-shelf (widely available) bi-dimensional indexes and enhanced by a segmentation stage. The proposed system does not restrict the choice of the parameters of range queries at query time, unlike clustering and similarity-based methods do. The experimental results, obtained on a standard PC-based system both on a well known real-world trajectory dataset and on synthetic data, confirm the efficiency of the proposed approach.