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. 14. 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; determine a familiarity distribution function associated with the user history for calculating a user familiarity estimate for the system user regarding a location not included in the user history; and generate the user geographic-knowledge model based on the user familiarity estimate and the familiarity distribution function.