Method for operating a navigation device with speed data that can be updated separately

The method involves determining position of a navigation device, and defining a selection area under consideration of the position. An outlet road segment is selected from a set of road segments arranged in the selection area, where the road segments are assigned to map data. A reference road segment is selected from another set of road segments. Identification parameter of the outlet road segment and speed information of the reference road segment are stored in a reference database such that the parameter is combined with the speed information. An independent claim is also included for a navigation device.