本发明提供一种导航设备(200)，其可操作以产生一表示旅途条件是否有利之输出指示，该导航设备包含一处理资源，其经组态以：判定(660、661)在一第一预定时间穿越一导航路线之至少一段的第一旅途时间信息；判定(662、663、664)在一不同于该第一预定时间之第二预定时间穿越该导航路线之该至少一段的第二旅途时间信息；自该第一旅途时间信息及该第二旅途时间信息判定(666)一表示旅途时间之一演变特性的旅途时间参数；及回应于该旅途时间参数，产生表示旅途条件是否有利之该输出指示。

A navigation device (200) operable to generate an output indication representing whether or not journey conditions are favourable, the navigation device comprising a processing resource configured to: determine (660, 661) first journey time information for traversing at least one segment of a navigation route at a first predetermined time; determine (662, 663, 664) second journey time information for traversing said at least one segment of the navigation route at a second predetermined time different from said first predetermined time; determine (666) from said first and second journey time information a journey time parameter representative of an evolution characteristic of journey time; and generate, responsive to the journey time parameter, said output indication representing whether or not journey conditions are favourable.