Cost of Road Traffic Accidents (DTCC Study WP D1)

The Ministry of Transport's Domestic Transport Costs and Charges (DTCC) Study (2021-23) aimed to improve our understanding of the costs of the provision and use of New Zealand’s domestic transport system. It also looked at costs relative to the charges or burdens facing transport users to improve our understanding of the economic, environmental and social costs associated with different domestic transport modes and movement types.

ViaStrada were commissioned to derive estimates of the costs of road transport-related "accidents" in New Zealand (for both motorised and non-motorised users). Following a review of the relevant literature and available data, the work first explored the overall costs associated with road accidents (to both motorised and non-motorised users) in New Zealand, and the average costs per vehicle-km, net tonne-km or person-km where possible. The next part looked at the "marginal" costs and charges (i.e. the unit variable costs of changes to the current transport volumes) and also explored further the payment streams (i.e. who ultimately pays for the costs involved with transport accidents).

This working paper (WP D1) summarises the methodology and calculations to derive estimates of the Total (Social) Costs, Average Costs, Marginal Costs and Marginal Externality Costs of road transport-related accidents in NZ. As well as aggregate cost calculations, the analysis considers the various inter-relationships between the funding and charging for costs related to accidents. This includes the roles of the Accident Compensation Corporation (ACC) and private insurance to cover many of the medical, work-interruption, and property damage costs associated with road accidents and other transport mode accidents (otherwise largely borne by individuals, employers and the public health service).