The railway is one of the lifeline systems of India’s transportation infrastructure. The prospective growth of high-speed trains in India is prominent in alleviating road congestion and fostering urban business activities. However, these high-speed trains are constructed on ballastless tracks and generate significant vibrations, which may damage the infrastructure in close proximity, and/or bring in discomfort to the occupants of these infrastructure. One of the proven effective solutions to dampen these vibrations is ballastless track system with sandwiched cement asphalt mortar (CAM) layer. Countries like Germany, Japan, and China have successfully employed CAM layers to mitigate vibrations in high-speed rail systems. Various CAM mixes provide different degrees of isolation. However, their applicability to various field condition requires numerical modelling and initial effectiveness verification. This paper explores various mechanical and physical properties of CAM that can be used in numerical modelling. This paper also presents various numerical and experimental studies conducted in CAM mix for high-speed train vibration isolation, and the results are critically reviewed.