Large cyclic stresses induced from heavy traffic can cause significant degradation of rail tracks, leading to poor track geometry and safety. Inclusion of resilient materials such as geosynthetics to reinforce the track substructure has been observed in the laboratory to be viable at reducing the impact of such adverse effects. Despite this, the ‘field’ performance of different geosynthetics to reinforce ballasted tracks has not been investigated in a systematic manner. An extensive field study was therefore undertaken on experimental track sections near Singleton, New South Wales. Four types of geosynthetics were installed at the ballast-subballast interface of track sections constructed on subgrades with three distinctly different values of stiffness. It was found that geogrids can decrease vertical strains of the ballast with obvious benefits of improved track stability and reduced maintenance cost. It was also found that a few selected types of geogrids can be effectively used for soft subgrade soils.