The economic impact of road closures caused by natural hazards - case study Kaikoura

Abstract

The New Zealand road network is vital to the economic wellbeing of the nation. The road network is, however, vulnerable to closure from a host of natural hazards. Road closures caused by natural hazards adversely effect the movement of freight and people between nodes. Link security is of particular importance to communities separated from major urban centres, particularly when alternative road links (if any) condition costly deviations.

This research investigates the vulnerability of the road network in the Kaikoura District to closure from natural hazards and estimates the costs of road network disruption for road-users and non-users. The road network in the Kaikoura District is sparse and has historically been disrupted by natural hazards. The 'potential' cost of road network disruption for road-users and non-users exceeds $0.25 million per day when road-users are required to detour to the Lewis Pass route. However, total disruption costs are significantly lower when a low-cost alternative route (Highway 70) is available.

Link reinstatement priorities are provided according to road-user cost and non-user cost minimisation and the strategic importance of the State Highway 1 link to the north of Kaikoura has been emphasised. It is recommended that a New Zealand wide risk analysis study be conducted to provide a cohesive and comprehensive information base applicable to the management of the New Zealand road network.