This paper gives a brief introduction on the background and current status of landslides along the mountain roads in Taiwan. Based on the inherent factors and man-made factors of failed and not-yet-failed slopes, an approach for mountain road slope maintenance is proposed. It includes the establishment of a Slope Management System (SMS), setting up monitoring system for large scale landslides, and proposing a landslide hazard mapping method using the probability of a slope failure. The probability of failure is determined by inputting the inherent factors of the slope and the triggering factor of rainfall to a statistical evaluation model. Gaussian processes are used as the statistical model to predict where and
at what potential and probability of a slope is to fail. However, the typhoon induced rainfall in the mountain area is affected by several factors such as the path of typhoon and the location of a slope etc.. It is still difficult to predict when a slope failure will occur so far. More rainfall records are needed to get a better idea about the possible amount of rainfall at a specific slope site during a typhoon.