1. A navigation system included in an item, comprising: a route selecting unit to select an optimal route to a destination point for traversal by the item based on calculated performance indexes of a plurality of alternative routes to the destination point for the traversal; a performance index calculating unit to recalculate the performance indexes of the alternative routes during a current traversal of the selected optimal route based on received congestion information from a remote device, remote from the navigation system, of respectively identified sections of available traversals after a predetermined point in each of the alternative routes beyond a current point of the current traversal; a requesting unit to request, from the remote device, congestion information regarding each of the respectively identified sections of the available traversals after the predetermined point in one or more of the alternative routes beyond the current point of the current traversal; and a route changing unit to selectively update the optimal route during the current traversal based on the recalculated performance indexes, wherein the remote device provides congestion information on a plurality of positions or sections to one or more items for respective item traversals, and wherein the item and the one or more items are mobile devices.