The Quantitative Assessment of Debris Flow Risk to Road Users on the Scottish Trunk Road Network (2)

This report presents a Quantitative Risk Assessment (QRA) for the impact of debris flow on the A85 road at Glen Ogle in Scotland. The methodology was developed and first used on the A83 Rest and be Thankful site, also in Scotland. The methodology considers the probability of an event of a typical size, and the conditional probabilities of a vehicle being affected, given an event, and of damage (fatality) occurring given that the vehicle is affected.