1. A navigation device, comprising: a processor; and a memory store containing map data, the map data being modified with predetermined temporal information for a predetermined time period to include a temporally-variable feature, the predetermined time period including a start time and an end time or a start time and duration, a weight or cost attribute for each road segment associated with the temporally-variable feature, and the processor being arranged to: determine, in a route planning process, a status of the temporally-variable feature according to the temporal information, wherein the weight or cost attribute for at least one high capacity road within a predetermined distance from the temporally-variable feature is reduced to avoid a selection of low capacity roads in the route planning process between a start location and a destination location according to the status; and provide at least one route determined in the route planning process.