Using Census data to travel through time in New Zealand : patterns in journey to work data 1981-2006

Aim: Little comprehensive longitudinal evidence exists regarding the association between work-related travel modes and oil prices for the New Zealand population. Accordingly, the objective of this study is to document work-related travel behaviours in New Zealand adults and oil prices over time. Examining this relationship may lead to a greater understanding regarding how best to promote sustainable transport modes, which is important for improving public health outcomes, such as increasing physical activity engagement, enhancing air quality, and reducing traffic-related injuries. Method: Work-related travel data were obtained from the New Zealand census of population and housing conducted quinquennially from 1981–2006. These travel data were compared with 2006-adjusted oil prices. Results: Private motor vehicle was the dominant travel mode across years (54.8%– 79.9%). The proportions of trips by public transport (~4%) and active transport (8.9%–14.2%) were low across all time points and steadily declined. Oil prices decreased from 1981 to 1996, and increased from 1996 onwards.Conclusion: A decline in work-related sustainable transport modes over the last 25 years in New Zealand was evident. Work-related private motor vehicle travel may be sensitive to oil prices, however, further research is required to fully understand this relationship. Future research in this field should seek to increase levels of sustainable work-related transport modes, further understand oil price elasticity across different groups, and to determine whether behaviour changes are short-term or have a lag. Public health agencies should seek to advocate for infrastructure that supports sustainable transport modes and conduct further research in this field.