1. Trajectory data retrieval system ( 1 ) for retrieving trajectory data of moving objects in a plurality of image sequences, the trajectory data retrieval system ( 1 ) comprising a database ( 4 ) realised for storing a set of common routes based on the trajectories of the moving objects, whereby each subset of the set of common routes is generated by a plurality of trajectories and whereby each subset is linked with the trajectory data of its generating trajectories and/or parts thereof and/or of trajectories overlapping at least in part with the subset, querying means ( 7 ) realised to formulate a trajectory-based query characterized by retrieval means ( 8 ) realised to retrieve trajectory data linked to a matching subset of the set of common routes matching with the trajectory-based query.