Speed interface to Navigation System

I recently purchased a 2011 Edge with the navigation installed. I noticed the when you are driving on a US highway the speed limit is posted. It would be great to have that coupled to the cruise control. I would allow any + or - bias to stay with the cruise control setting. Say the speed limit is 65 and you have 60 set and the speed limit drops to 55. Than have the vehicle set a new speed of 50. I think the navigation system audio should say "speed limit change" to alert you of the change.
Bobby M 01/10/2013
I'd be happy if it would just alert you to being over the speed limit.