Landslide risk of regional roads: Consider the road mileage of expected losses

Considering the road disruption caused by landslides, this study develops a quantitative method to evaluate the landslide risk encountered by regional roads. First, a logistic regression model was performed to evaluate the landslide possibility with nine landslide factors and 359 landslide samples. Subsequently, network self-adjustment and three vulnerable factors were integrated to depict road vulnerability. After determining the cost of different road sections, the landslide risk of roads was calculated and expressed as a potentially expected loss. Results show that the study area highlights the road segments with low landslide risk, focusing on the expected loss of 0.0–0.1 million CNY; while lines of Tahe-Great Khingan-Mohe and Mohe-Huma maintain the highest risk, and the expected loss exceeds 0.8 million CNY. Furthermore, the lower the road class, not only the greater the expected loss, but the higher the road mileage exposed to landslides, which facilitates the mitigation strategy for different types of roads in response to landslides.