Risk and Impact of Natural Hazards on a Road Network

Abstract

This paper describes a study to investigate hazards with the potential to close the Desert Road section of New Zealand's major north-south road link, State Highway 1. The risks caused by snow and ice, volcanic eruptions and lahars, earthquakes, and traffic accidents were evaluated in terms of their expected frequency of occurrence and duration of road closure. The effects of road closures on traffic flow patterns were assessed using a traffic assignment model, with and without allowing for the elasticity of travel demand. A probability distribution for the annual economic impact of road closure was found for each hazard. The viability of various mitigation options for reducing the risk of road closure was assessed, using probability distributions of the benefit-cost ratio for the mitigation options.