Urban sprawl has been widely discussed in regard of its economic, political, social and environmental impacts. Consequently, several planning policies have been placed to stop—or at least restrain—sprawling development. However, most of these policies have not been successful at all as anti-sprawl policies partially address only a few determinants of a multifaceted phenomenon. This includes processes of extended suburbanisation, peri-urbanisation and transformation of fringe/belt areas of city-regions. Using as a case study the capital city of Chile—Santiago—thirteen determinantsof urban sprawl are identified as interlinked at the point of defining Santiago's sprawling geography as a distinctive space that deserves planning and policy approaches in its own right. Unpacking these determinants and the policy context within which they operate is important to better inform the design and implementation of more comprehensive policy frameworks to manage urban sprawl and its impacts.

Urban sprawl has been discussed extensively with regard to its negative impacts. On this basis, regulations have been put in place to control sprawling suburbanization, including the establishment of restricted areas for expansion defined by administrative urban boundaries. Overall, these measures have not been at all successful, considering that city-regions continue to expand inorganically, often reinforcing urban sprawl patterns. As clear evidence of the weaknesses of planning regimes of control, these unsuccessful attempts are partly explained by a series of policy ambiguities that contradict the meaning of planning as a prescriptive discipline. This ambiguity is justified by the need to frame flexible regulations that allow adaptation to unforeseen events over time. In this paper, using the case of Auckland, New Zealand, it is demonstrated that instead of planning flexibility, there is planning “ambiguity” accompanied by weak opposition from rural regimes, which deliberately contributes to urban sprawl. This is relevant considering that the inorganic encroachment of rural lands diminishes the huge environmental potential of the peri-urban space of Auckland, its ecosystem services, and agricultural activities—all elements that encourage the creation of more environmentally sustainable peripheral landscapes as a counterpoint to traditional sprawling suburbanization.

Urban sprawl has been mainly discussed in regard to its negative impacts. However, there is a variety of rural lands that benefit the suburbanization process in social, environmental, economic and political terms. These lands configure a category of rurality rarely considered as part of the urban phenomenon, and usually seen as pending space for further (sub)urbanization. In this sense, planning regimes and institutional changes tend to transform suburban rurality into marketable residential space, triggering reactions of preservation and change. With regard to the capital city of Chile – Santiago – it is argued that the meanings about the “urban”, the “rural” and the “city” become disputable in the light of suburban rurality and problematic as direct antonyms or unequivocal synonyms. It is also demonstrated that despite dramatic institutional changes, suburban rurality can survive over time if it finds support in social organizations and alternative planning rationales. The research in which this paper is based was conducted in five years and included the revision of several leftover interstitial spaces in which suburban rurality emerges as one of the most meaningful categories of suburban space. To gain further understanding on suburban rurality, this paper is based on a qualitative approach – including semi-structured interviews and archival revision of historical documents and policy reports – and focuses on the southern geographical space of the metropolitan area of Santiago de Chile, where most of social housing developments have been located over the last 60 years.

Urban sprawl in Latin America is described as one of the major problems of ‘the growth machine’. As a reaction, most planning policies are based on anti-sprawl narratives, while in practice, urban sprawl has been thoroughly consolidated by all tiers of government. In this paper – and using the capital city of Chile, Santiago, as a case study – we challenge these anti-sprawl politics in light of the emerging environmental values and associated meanings of the interstitial spaces resulting from land fragmentation in contexts of urban sprawl. Looking at the interstitial spaces that lie between developments becomes relevant in understanding urban sprawl, considering that significant attention has been paid to the impact of the built-up space that defines the urban character of cities and their governance arrangements. We propose that looking at Santiago’s urban sprawl from the interstitial spaces may contribute to the creation of more sustainable sprawling landscapes and inspire modernisations beyond anti-sprawl policies. Finally, it is suggested that a more sustainable urban development of city regions might include the environmental values of suburban interstices and consider them as assets for the creation of more comprehensive planning and policy responses to urban sprawl.

Streets and roads have been constantly identified as key spaces to improve walkability and—by extension—the entire urban environment. Such improvements lie on planning and design theories that are often supported by qualitative evidence and as such, tend to remain highly speculative on how street design influences walkability in more deterministic ways. Drawbacks in further exploring this street-walkability correlation are partly defined by an explicit rejection to ‘spatial determinism’ in urban morphology and social sciences, but also because combining differing epistemological approaches for understanding social processes linked to the physical aspects of the space is complex. In this paper, it is proposed that qualitative (social-based) theories of the space and quantitative (positivist) understandings of people’s behaviour can complement each other to elaborate upon ‘spatial determinism’ with focus on streetscapes and pedestrian behaviour. By using Agent-Based Modelling (ABMs), morphological components of streets linked to population characteristics are analysed to understand walkability from the perspective of spatial determinism. The findings suggest that the street settings directly affect pedestrian behaviour, and that changes in the built environment result in changes on walkability patterns. Ultimately, the modelling exercise shed light on street design and walkability, but also on wider debates on how urban design and social processes correlate in more deterministic and, therefore, predictable ways.