Land use, transport, and population health: estimating the health benefits of compact cities

Abstract

Using a health impact assessment framework, we estimated the population health effects arising from alternative land-use and transport policy initiatives in six cities. Land-use changes were modelled to reflect a compact city in which land-use density and diversity were increased and distances to public transport were reduced to produce low motorised mobility, namely a modal shift from private motor vehicles to walking, cycling, and public transport. The modelled compact city scenario resulted in health gains for all cities (for diabetes, cardiovascular disease, and respiratory disease) with overall health gains of 420-826 disability-adjusted life-years (DALYs) per 100 000 population. However, for moderate to highly motorised cities, such as Melbourne, London, and Boston, the compact city scenario predicted a small increase in road trauma for cyclists and pedestrians (health loss of between 34 and 41 DALYs per 100 000 population). The findings suggest that government policies need to actively pursue land-use elements-particularly a focus towards compact cities-that support a modal shift away from private motor vehicles towards walking, cycling, and low-emission public transport. At the same time, these policies need to ensure the provision of safe walking and cycling infrastructure. The findings highlight the opportunities for policy makers to positively influence the overall health of city populations.

Figure 1. Land-use, transport mode choice and population health model.

Figure 2. Illustration of the terms density, distance, and diversity as applied in the land-use, transport, population health model.

Figure 3. Vehicle kilometres travelled (VKT) by mode in each city at baseline with dominant transport odes (>15% of total VKT) highlighted.

Figure 4. Estimated change in total kilometres travelled per day by mode of transport under the compact cities model for each city.

Figure 5. Estimated change in road deaths and recorded injuries under the compact cities model for each city per year.

Figure 6. Estimated effect of additional separation of active transport VKT from traffic required to offset additional road trauma DALYs for each city under the compact cities scenario (positive numbers represent estimated increases in road trauma).

Figure 7. Extensive infrastructure in cities such as Helsinki is being delivered to support greater levels of safe cycling.