Given a railway line with n stops and the number of travelers between each pair of stops, we show how to split these stops into k different fare zones in order to maximize the benefit obtained from the sale of tickets to the travelers. We present a method to obtain this solution that is based on finding the longest path in a weighted root tree. This method improves in terms of efficiency the combinatorial method, where all the possible distributions have to be considered for deciding which is the optimal one. ; MEC Project [MTM2013-47093-P] ; MEC Project [MTM2012-33073] ; Conejero Casares, JA.; Jordan Lluch, C.; Sanabria Codesal, E. (2014). A tree-based model for setting optimal train fare zones. Mathematical Problems in Engineering. 2014:1-11. doi:10.1155/2014/384321. ; Senia ; 1 ; 11 ; 2014