Highway construction and maintenance in the mountainous regions is difficult and costly because of rugged topography and fragile geology. Because of rugged topography and fragile geology various types of natural disasters including landslides, slope failures, flood, and earthquake are very common in the mountainous regions. Roadside slope failure along roads is a common problem in the mountainous regions as road construction activities disturb naturally formed slope. Realizing this fact, an attempt is made to incorporate slope failure susceptibility conditions in highway alignment optimization model and integrated highway maintenance prioritization model in this book.