In order to develop the social and economic of East Malaysia, the local government decided to upgrade Pan Borneo highway. The main issue of the highway design is the weak soil of the road subgrade. The geological of road subgrades are formed by four layers, the top two layers are peat and soft clay which may cause serious rutting and deformation of road structure. To avoiding the problems, the design was adopted high strength PET geotextile to be the reinforcement and low elongation PP geotextile as the separator to increase the stability of the whole road structure.