A Car Navigation System for Linux and UNIX RoadMap is a program that displays a map of the streets, tracks the position provided by a NMEA-compliant GPS receiver, identifies the street matching this GPS position and announces the name of the crossing street at the next intersection. A rudimentary trip feature allows RoadMap to display some basic navigation information. The map files used by RoadMap are generated from the TIGER files (US Census Bureau) and the Digital Charts of the World.