This report discusses current techniques used to evaluate landslide hazard in three stages.

Firstly, the landslide hazard of an area is evaluated by collecting existing data, field reconnaissance, etc.

At several specified sites along a route, more detailed investigations are then conducted, such as geophysical exploration, borings and stability analyses. The results are used to evaluate the landslide hazard at the sites more precisely and to design works to prevent possible landslides.

Thirdly, monitoring is conducted during construction and after opening highways to prevent landslides problems.