11. A navigation system comprising: a control circuit configured to: receive user input regarding a navigation route for controlling guidance communication along the navigation route for a system user wherein the user input corresponds to a passive-navigation portion for representing one or more locations of the navigation route not requiring communication of the guidance communication for the system user; generate a user geographic-knowledge model based on the user input regarding the navigation route; calculate a system route based on the user geographic-knowledge model; communicate the system route for guiding the system user in traversing the system route; and a storage circuit, coupled to the control circuit, configured to store the user geographic-knowledge model.
11. A navigation system comprising: a control circuit configured to: receive user input regarding a navigation route for controlling guidance communication along the navigation route for a system user wherein the user input corresponds to a passive-navigation portion for representing one or more locations of the navigation route not requiring communication of the guidance communication for the system user; generate a user geographic-knowledge model based on the user input regarding the navigation route; calculate a system route based on the user geographic-knowledge model; communicate the system route for guiding the system user in traversing the system route; and a storage circuit, coupled to the control circuit, configured to store the user geographic-knowledge model. 12. The system as claimed in claim 11 wherein the control circuit is configured to: determine a user history based on the navigation route for representing locations previously visited by the system user; calculate a point density based on the user history for representing concentration of locations previously visited by the system user; and generate the user geographic-knowledge model based on the point density for estimating a familiarity of the system user for a geographic area.