1. A method comprising: receiving mobile phone operational data indicative of user equipment location, the mobile phone operational data comprising location area update messages and periodic registration messages: filtering the mobile phone operational data based on time and area to select a portion of user equipment location information to produce filtered mobile phone operation data; performing travel estimation based on the filtered mobile phone operation data, including performing interpolation on data associated with one or more individuals in a population to estimate intermediate positions of a trajectory of each of the one or more individuals for a specified time period using a shortest path estimation algorithm that determines a shortest path between pairs of points based on geographic information associated with the user terminals, weights associated with geographic areas, and probabilities associated with likelihoods of a user terminal moving between geographic areas; and counting a number of individuals in population at a given time and at a given area.