Event tree analysis and comparison for mountain roads under rockfall hazard

Rockfall is one of the most hazardous and dangerous landslide phenomena, which can significantly affect mountainous roads. To the knowledge of the Authors, limited studies focus on the quantitative risk assessment to pedestrians and vehicles along mountain little traffic roads. A method tailored to these elements at risk is herein presented and applied to a real case. The calculation method is based on the Event-Tree Analysis, through which all the scenarios which can lead to a fatality or injuries are investigated. An application on a study case in the Italian Alps illustrates the potentialities of the methodology.