Navigation system using forward-looking origin selection for route re-calculation

The present invention relates generally to navigation systems and more specifically to an improved navigation system for calculating an alternate route. A navigation system calculates a first route to a first destination. If the navigation system determines while en route that a second route would result in a significant time saving, the navigation system selects a point along the first route between the current vehicle location and the first destination as a new "origin" for the second route. The navigation system guides the user to the intermediate point along the first route. The navigation system then guides the user from the intermediate point along the second route. The second route can be an alternate route to the same destination or an alternate route to a second destination.