Abstract: A navigational system and a computer-based datalogger are used to store data on the distances traveled by and places visited by a monitored vehicle. The datalogger includes a clock and an on-board memory that can store time-stamped records of the latitude and longitude of places visited by the vehicle. In some such systems the vehicle operator can assign a label or a location classification to selected places that he or she visits. Additionally, in some versions of the system an administrator can use a central computer located at the vehicle's home base to assign labels to locations where the vehicle is expected to make a stop. The central computer generates a map-like graphical output that displays a point corresponding to each of the places visited. This display may also show the time spent at each place visited during an operational period.