Methods and apparatus are provided for generating route instructions on a turn-by-turn navigation system in a vehicle. Turn instructions can include a turn icon as well as visual and audio prompts. The turn-by-turn navigation system typically includes a dual-use disk changer configured for both audio and Map/POI disk access. Separate Map and POI database disks are typically installed in dedicated slots of the disk changer and are designed to minimize switching time, while audio disks can be installed in the remaining slots. Moreover, audio playback buffering can be employed to enable audio-to-navigation-to-audio disk switching without interrupting audio playback. The turn-by-turn navigation system can generally be produced more economically than a typical premium system with a full complement of costly features, such as a color map display, since the turn-by-turn navigation system can be configured with only those features deemed most useful to a broad-based market segment.