JIBE Joining Impact models of transport to spatial measures of the Built Enviornment

Lead Research Organisation: University of Cambridge
Department Name: MRC Epidemiology Unit

Abstract

The kinds of cities we live in affects our health through influencing the choices we make and environments we make them in.

For example, having a choice of local destinations within walking distance makes it more likely that people will walk, and thus increase their physical activity. Living on, or near busy heavily trafficked streets means people are exposed to higher levels of air and noise pollution and may increase the risk of road trauma, as those roads are more dangerous to cross.

In turn how physically active (e.g. from walking and cycling) we are and how much we are exposed to air pollution, noise pollution, and greenspace all affects our risk of developing diseases like heart disease, stroke, and cancer.

Policy makers and planners in Australia and the UK are looking at a range of transport and land use policy options to try and create healthier and sustainable cities. This is often to referred to as improving an important element of 'liveability', to express the idea that this will make people's lives better in a range of ways. By testing and estimating the health impacts of several options, we can inform city planners and public health practitioners about what would have the greatest chance of promoting good health and reducing health inequities.

This project brings together experts from Australia and the UK who have 1) analysed how urban liveability varies from place to place and who gets to live in more liveable places; 2) examined associations between the built environment and transport and other health-behaviours; and 3) developed computer models to estimate the health impacts of changes in how people travel.

While much work has been done, there are still gaps in what we know. In England, we do not have consistent measurements of many important liveability factors, for instance how easy it is to get to the shops in different neighbourhoods. This means we have not been able to use computer models to predict what might happen to people's health if these factors changed. In turn it has been hard for planners to make changes in land use and transport policies, because we have not had the evidence showing which changes will benefit health most. We are therefore missing information on the health impacts of changing the way we design communities, and an assessment of the winners and losers.

In contrast, in Australia researchers have developed detailed measures of liveability. However, comprehensive studies linking possible changes in liveability to health outcomes are still missing.

This project will bring together UK and Australian expertise to overcome these gaps, and to help policy-makers create healthier and more liveable cities. We will develop new liveability measures for the eleven devolved city regions in England. We will use these to characterise and compare different neighbourhoods in terms of how healthy they are for their residents. For every postcode in these England city regions and in Melbourne, Australia we will create a virtual population of individuals with travel patterns and levels of exposure to air pollution, noise pollution, greenspace, and physical activity. In both countries we will improve and develop computer models that link changes in liveability to the best available evidence on how these factors affect health.

The project involves working closely with policy-makers and planners in both countries, to ensure the research results are relevant and feed into policy. We will model the results of a range of policy options that policy-makers are considering. The policy options will vary. Some will be more ambitious than others; some will focus on changing land use (like ensuring people have more local services); and some on providing more sustainable transport options like cycle tracks or bus services. Our goal is to support policy in making healthier cities, through a more scientific understanding of which policies do most to benefit health and reduce inequities.

Technical Summary

Creating healthy, sustainable, 'liveable' cities is a priority in Australia and the UK. The built environment (BE) in cities - including population density, proximity to shops and services, greenspace, and the street and road network influence distribution of non-communicable diseases (NCDs) risk factors across populations. The BE shapes risk factors for NCDs including physical inactivity, and air and noise pollution. BE factors also affect traffic injuries.

In response to growing concerns about preventable NCDs and policy interest in creating healthier more sustainable cities our research groups in Australia and the UK have undertaken high impact policy-relevant research by
1) conceptualising, measuring, validating, mapping and identifying inequities in the spatial distribution of measures of urban liveability;
2) examining associations between the BE and transport and other health-behaviours;
3) creating models to simulate health risks and benefits of shifting away from car travel to active modes (walking and cycling) and public transport.

However, in England these impact models have not been linked to detailed BE measures assessing liveability. This means we are not able to assess current variations in, or health impacts of scenarios of new BE interventions across the population. In Australia, comprehensive BE measures assessing liveability have been developed, but these have yet to be linked to state-of-the art health impact models.

Together we will overcome these limitations by creating new BE measures for city regions in England and linking these to an improved health impact model, and linking our BE measures in Australia to a version of this improved model.

Our aim is to create high impact informative research that speaks directly to the needs of stakeholders. By testing co-designed urban and transport planning scenarios and estimating their health impacts, we will inform debate and policy on reducing NCDs and health inequities.

Planned Impact

In Australia and the UK most people live in cities. The built environment (BE) of these cities and how people move around has major implications for population health. There is increasing alarm on the environmental impacts of greenhouse gas emissions from transport, and growing concerns about the health impacts of the air that we breath. Regular exposure to traffic noise is not just annoying but increases the risk of heart disease. Access to greenspace is good for mental and physical health. Road traffic collisions still cause many preventable deaths and life changing injuries. At the same time cycling and walking for transport provide a potentially convenient way to incorporate physical activity into everyday life, offering a sustainable form of transportation with health and environmental benefits. Tackling these problems in an integrated way by changing their causes, could bring large public health benefits. However, policies are typically narrowly focused and piecemeal. There is a missed opportunity to generate greater overall health benefits through joined up working. Detailed and integrated assessments of benefits and trade-offs can inform the case for investment.

The methods we will develop and apply in this project will improve estimation of how the BE would affect travel behaviours, how this would alter exposures to air pollution, greenspace, noise, injuries and physical activity, and in turn, how these changes would impact population health. By providing locally detailed results, policy relevant models, and estimates of how confident we can be in each result we will support evidence-informed policy-making and health-promoting policies.

This project will provide numerous benefits. It will provide estimates of how supportive the BE of cities in England and Melbourne is for health and sustainable transport and identify what kind of changes could be realistically be achieved. Co-designed with decision-makers, new evidence will be created of the potential health benefits and harms of BE scenarios designed to shift travel behaviours, including how this might affect health equity.

Key beneficiaries in the UK will be the Department for Transport, Public Health England, Sports England, and the city region combined authorities. It will help city regions in assessing the health impacts of their transport and land use planning policies. It will help them develop quantitative planning guidance, e.g. what level of population density and destinations are required to make a walkable city. In Australia, key beneficiaries include the Federal Departments of Infrastructure and Health and Human Services; the Victorian Departments of Transport and Health and Human Services; the Victorian Planning Authority, and Infrastructure Victoria.

On a larger scale, availability of the model code will benefit researchers, and technical experts in national and international policy organisations and local government looking to apply or develop the methods elsewhere.

Many of these urban development problems are even more pressing in rapidly urbanising lower and middle-income countries. This project will complement the impacts being generated by Global Challenge Research Fund work (e.g. Dr Woodcock's Tigthat project) by providing a data test bed that can support research in how to adapt the methods for other settings.

For details on how we aim to disseminate knowledge from these methods to potential users, see Pathways to Impact and Communications Plan.

Joining up and enhancing some of the most advanced health impact modelling, with the most detailed understanding of how the BE impacts behaviours, and a dedicated approach to ensuring relevance and dissemination of the research for decision-makers, this project offers a unique opportunity to support health promoting land use and transport policy solutions.

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