Provided is a critical point method used to determine the points of a real-time stream of location data, such as Global Positioning System (GPS) data, that should be retained based on their importance in reconstructing the travel path of a mobile device. The method may run on a mobile device or on a server. When run on a mobile device, the method reduces the amount of data transferred between mediums by only transferring points that are critical to reconstructing the path of travel of the mobile device. This reduction saves power used in the wireless transmission and reception of the non-critical data and the bandwidth used while transmitting non-critical data. The method may be run every time a new position is calculated. When a new position is determined to be a critical point, the point is transmitted. If the new position is not a critical point, then the point is discarded.