when the navigation is interrupted for example by the call and then u go back to program, it stop using gps. i have to restart gps in menu or restart the program. the time of travel is double or sometimes only 1 minute, but for 3hrs. can't add home place for quick navigation. dunno how it's using the traffic info, because it can lead u to the jam. i can't somehow report the problem on the road as in waze to help the others