The paper discusses a research and development work related to investigation of the geogrid-granular soil interaction in transportation applications such as road or railways at the Department of Transport Infrastructure of Széchenyi István University (Gyor, Hungary). Utilizing special laboratory multi-level shear box tests different geogrids and geocomposites with various kinds of nonwovens and connection types will be analyzed with different soil types (different soil types for road subbase & different ballast and sub-ballast types). The authors will investigate the internal shear resistance of the different soils with and without geogrid reinforcement in the same circumstances, which shows the efficiency of the interlock effect and the effective zone of influence of the grid at regular intervals away from the grid/soil layer. Previous results from the same equipment have been prepared for a wide range of geogrids (raw material, aperture size, type of production processes, etc.) which will help the authors fully understand the complex soil/grid interaction and interlock effects.