Method for operating a navigation device in a vehicle and navigation device

The method involves determining position of a vehicle (101) and determining the position related to a preferred lane by using the map data. The position related to a current lane, on which the vehicle travels, is determined by using an image recording unit (104). A test step is performed considering the preferred lane and the current lane so that a test result is provided, where route instruction is displayed by using an output unit. An independent claim is included for a navigation device.