Abstract
Two auto accidents involving heavy duty trucks, occurred in the same season and in the same place on a mountainous road within two years. Where the trucks rolled over and slid off the road and down a hill. These accidents were caused by a problem with the braking system called "Fade Phenomenon". These accidents took place in the same place as others in the past where braking system problems such as "Vapor Lock" or "Fade Phenomenon" had occurred. Therefore, an examination of these factors took place. The results showed that such accidents are influenced by the road environment and weather conditions.
