A method and system for calculating the approximate location of a mobile station along a recurrent route is disclosed. In an embodiment for the method in accordance with the principles of the present invention, the method for storing reference data includes decoding a first unique identifier for a cell in communication with the mobile station at a first location and a first time, storing the first unique identifier and the first time, decoding, upon handoff to a next cell, at a second location and at a second time, a second unique identifier for the next cell, and storing the second cell identifier and the second time. In a method for calculating an estimated time of arrival at the endpoint of a segment for a mobile station traveling along a recurrent route of travel, the method includes detecting the startpoint of one of the plurality of segments at a first time, and calculating an estimated time of arrival at the endpoint of the segment. In an embodiment of a system in accordance with an embodiment of the invention, the system includes a mobile station, a first cellular base station, a second cellular base station, a database, and a processor.