Population health, health equity and health system impacts of light vehicle electrification: a modelling study in Aotearoa/New Zealand.

Background: Electrification of the light vehicle fleet is a core component of decarbonisation policy globally. As transport is an important determinant of health, this process will likely impact a range of pathways to population health, outside of averted climate change.

Methods: A transport-health multistate lifetable model for Aotearoa/New Zealand was used to model changes in the vehicle fleet and transport behaviour patterns that could be expected as part of electrification in Aotearoa/New Zealand. These changes are related to the new energy source and the costs of driving. The potential health, equity, health system cost and environmental impacts of this transition were modelled through the pathways of physical activity, injury and air pollution (tailpipe and non-tailpipe).

Results: Compared with a scenario of 2018 vehicles and travel patterns projected forward, under the electrification scenario modelled by 2050, there would be a 21% increase in per capita kilometres travelled by car, a loss of 270 health adjusted life years (95% uncertainty interval (UI) -1000 to 500) and health system costs incurred of NZ$44 million 2018 dollars (95% UI NZ$-12 to NZ$110). While health impacts from air pollution decreased, in the electrification scenario road injury increased and there was a net health loss. Increasing the cost of driving, through distance-based charging, attenuated the negative health impacts.

Conclusions: These results suggest that the electrification of the light vehicle fleet has mixed health impacts. Researchers and policy-makers should take a cautious approach to claims that light fleet electrification will have co-benefits for population health and health equity.