A prototype method to rate the link vulnerability of strategic rural roads

This paper presents a prototype method to rate strategic roads by link vulnerability. A strategic road is one that is most important for the fast and efficient movement of people and goods. Vulnerability is the weakness of the road network to successfully deliver this movement. The proposed method avoids the detailed risk analysis by comparing sections of road. A comparison is made by rating all of the links in a network for vulnerability, including the identification of weaknesses for each strategic road and the consequence that this weakness has on the network. Weakness is rated in terms of how exposed a road link is to closure. Consequence is rated in terms of the serviceability of the detour. Each rating is represented as a formula, and the two ratings are combined to yield an overall vulnerability rating for each road link in the network. The prototype method is a low-cost rating method to assess the vulnerability of a strategic rural road network. This method has been applied to a strategic rural road network of the central North Island of New Zealand and found to give sensible results. The developed application of a vulnerability framework to assess a road network helps to identify the weaknesses in a transport system; decision makers can then use this knowledge to get the best value out of road infrastructure investments.