Data transfer systems for vehicle event recorders are provided as: a vehicle event recorder, a vehicle event recorder resident memory, and upload module in conjunction with, a communication port suitable for coupling with, a portable memory device, a server computer datastore, a server download module in conjunction with, a similar cooperating communications port. The portable memory device is arranged to operably couple with the communications ports of both the vehicle event recorder and the server computer and to be repeatedly moved between the two. The upload/download modules are arranged to transfer data to/from the portable memory in an orderly fashion in which no files are removed from the vehicle event recorder resident memory without first having been successfully transferred to the server computer datastore.