摘要：Objectives. We examined whether people moving into a housing development designed according to a state government livable neighborhoods subdivision code engage in more walking than do people who move to other types of developments. Methods. In a natural experiment of 1813 people building homes in 73 new housing developments in Perth, Western Australia, we surveyed participants before and then 12 and 36 months after moving. We measured self-reported walking using the Neighborhood Physical Activity Questionnaire and collected perceptions of the environment and self-selection factors. We calculated objective measures of the built environment using a Geographic Information System. Results. After relocation, participants in livable versus conventional developments had greater street connectivity, residential density, land use mix, and access to destinations and more positive perceptions of their neighborhood (all P < .05). However, there were no significant differences in walking over time by type of development ( P > .05). Conclusions. Implementation of the Livable Neighborhoods Guidelines produced more supportive environments; however, the level of intervention was insufficient to encourage more walking. Evaluations of new urban planning policies need to incorporate longer term follow-up to allow time for new neighborhoods to develop. The impact of urban planning on health is well recognized 1,2 ; however, recent trends in physical inactivity, sedentary lifestyles, and obesity have placed a significant focus on the need for better evidence to guide future urban planning and policy to support active living. 3 Furthermore, global population growth combined with an estimated 80% of people living in urban centers 4 highlights the increased need to build and regenerate cities so that they are health promoting. The recent United Nations General Assembly resolution on the prevention and control of noncommunicable diseases identified physical inactivity as 1 of the 4 leading risk factors for noncommunicable diseases. 5 Solutions recommended to combat physical inactivity included environmental changes related to urban planning, active transportation, parks, and recreational spaces. 5 Indeed, urban design policies and planning regulations that support and encourage walking are recommended across sectors, including public health, transportation, and planning. 6–8 Nevertheless, most studies underpinning recommendations to date are cross-sectional, and very few have examined the impact of environmental change on walking. 9,10 There are few evaluations of policies designed to increase active living. 11–14 Studies of the impact of changes to community design and transportation infrastructure are difficult to design, and randomized controlled trials are not feasible. Thus, there have been calls for evaluations of natural experiments involving new transportation (e.g., congestion charging) or urban design (e.g., home zones) policies 11,15–18 with the aim of studying their impact on physical activity. A unique opportunity to evaluate a natural experiment of this type presented itself in 1998 when the Western Australian Department of Planning began trialing a new community design code aimed at increasing local walking and cycling. The Livable Neighborhoods Guidelines 19 are essentially a local interpretation of new urbanism. 20,21 New urbanism (or neotraditional planning) evolved as a response to the conventional suburban sprawl thought responsible for a range of negative consequences, including car dependence, pollution, and traffic congestion. New urbanism combines elements of traditional housing design in walkable, mixed-use neighborhoods, as opposed to the low densities and curvilinear street layouts that characterize conventional suburbs. 22 The Livable Neighborhoods Guidelines incorporate 4 design elements aimed at increasing local walking and cycling: (1) a community design (e.g., mix of lot sizes, mixed-use planning), (2) a movement network (e.g., interconnected street networks, access to public transportation, traffic calming), (3) public parklands (e.g., balance between neighborhood parks and larger playing fields), and (4) lot layouts (e.g., to maximize surveillance of streets and parks, increased densities around public transportation and activity centers). We examined whether people moving into a housing development designed according to the Livable Neighborhoods Guidelines engaged in more walking than do people who move to other types of developments, and we examined differences in the built environment features of development types and changes in walking.
