Landslides are geological hazards that claim lives and affect socio-economic growth. Despite increased slope failure, some constructions, such as road constructions, are still being performed without proper investigation of the susceptibility of slope mass movement. This study researches the susceptibility of landslides in a study area encompassing a major highway that extends from Taiping to Ipoh, Malaysia. After a comprehensive literature review, 10 landslide conditioning factors were considered for this study. As novel research in this study area, multi-criteria decision-making (MCDM) models such as AHP and fuzzy AHP were used to rank the conditioning factors before generating the final landslide susceptibility mapping using Geographical Information System (GIS) software. The landslide susceptibility map has five classes ranging from very low (9.20%) and (32.97%), low (18.09%) and (25.60%), moderate (24.46%) and (21.36%), high (27.57%) and (13.26%), to very high (20.68%) and (6.81%) susceptibility for the FAHP and AHP models, respectively. It was recorded that the area is mainly covered with moderate to very high landslide risk, which requires proper intervention, especially for subsequent construction or renovation processes. The highway was overlayed on the susceptibility map, which concludes that the highway was constructed on a terrain susceptible to slope instability. Therefore, decision-makers should consider further investigation and landslide susceptibility mapping before construction.

The overall tectonics of a terrain and landslide occurrences can be controlled using lineament analysis. In addition, understanding the deformational characteristics of the rocks in question cannot be overemphasized. The current work was carried out along Taiping to Ipoh stretch of the North – South PLUS Highway Malaysia and its environs to assess landslide vulnerability via lineaments and strain deformation analysis. Approximately 73 km stretch of the road was analysed. Classification of about 197 lineaments was done from very high to very low density classes applying class break procedures to signify their respective risk zones. Fry strain analysis method was then integrated by digitizing the centre of the grains from which reference lines angles and axial ratios of 16 photomicrographs of various lithologies obtained from field investigations were used to understand their strain deformational pattern. The lineament intersection point map shows its concordance with the strain ellipsoid. The major trend of the lineaments and fry strain ellipsoid were both found to be trending NE–SW. Congruity between the lineaments intersection density and the flattened higher degree of strain signified a risk prone zone and probable landslide trigger along the highway.