1. A computer-implemented method, comprising: under control of one or more computer systems containing memory and configured with executable instructions stored in the memory, accessing from the memory trajectory data representing tracked positions of a vehicle along a trajectory having a start point and an end point, the trajectory data including recorded times, and speed of the vehicle at different points along the trajectory; identifying one or more potential parking locations of the vehicle along the trajectory; dividing the trajectory into segments based, at least in part, on knowledge of the identified potential parking locations; map-matching the segments to corresponding road segments; accessing historical data stored in the memory representing spatio-temporal travel patterns of vehicles learned from historical trajectories of vehicles corresponding to the map-matched road segments; automatically inferring, by the one or more computer systems, a behavioral state of the vehicle for a segment or position within a segment, based at least in part, on a position, time of day, and speed of the vehicle corresponding to the segment or position within the segment, knowledge of the map-matched-road segment, and the historical data; repeating the accessing, identifying, map-matching, and inferring operations for a plurality of vehicles to identify trajectory data for the plurality of vehicles; and analyzing the trajectory data for the plurality of vehicles to attempt to identify a pattern, the analysis including detecting whether passengers of the plurality of vehicles travel between a first and second region at a frequency that is greater than a predefined threshold.