This paper offers an exploration of urban expansion from the point of view of the individual residents buying land, settling and living in new, rapidly growing peripheral settlements of Dar es Salaam, Tanzania. The findings suggest that the demand for affordable housing is the primary motivation for residents moving to the periphery. The demand for self-built, owner-occupier housing is especially significant initially, while the demand for non-ownership housing increases in importance later in the process. Income-related motives, on the other hand, are strikingly absent from settlement considerations. Urban residents settle in the periphery, even though income-generation is often tied to working somewhere else, namely in the central parts of the city. The paper proposes that the processes of urban expansion depicted in this study are usefully conceptualized as suburbanization processes, though it is a type of suburbanization that has some peculiarities given the particular context, where expansion happens informally and largely unguided by planners.

This paper offers insights from comprehensive case studies of rapidly growing peripheral settlements of Dar es Salaam. The paper explores how a broad range of services and infrastructures have developed and improved over time, and how residents have been engaged in this in various ways. The gradual improvements in services and infrastructure are to some extent created, organized and financed by residents through informal self-help solutions, which are often costly and place huge strains on residents' time and resources. Alongside this, residents are also involved in attracting formal service providers through applications, co-financing of network extensions as well as lobbying efforts towards urban authorities and service providers. The formal service providers primarily take a reactive role, responding to demand, requests and political pressure from residents. Post-settlement network extensions are often complicated and impeded by costly and cumbersome land-acquisition processes, and because of the reactive and often piecemeal approach to network extensions, society may be missing out on potential benefits of scale. The way urban services work also means that the provision of services and infrastructure is extremely differentiated and fragmented across the urban territory, creating and reinforcing major inequalities in access to services.

This paper is concerned with access to the city for urban residents living in the periphery of Dar es Salaam, Tanzania. The paper presents an analysis of the mobility practices of residents and investigates the mobility constraints they experience in relation to the limited accessibility provided by the urban transport system. The paper draws upon qualitative interviews with residents in the periphery as well as recently collected travel speed data and offers a unique combination of testimony with GIS-based modelling of overall accessibility. A central finding is the overall importance of regular mobility and access to the city for residents in the periphery. Regular mobility is an ingrained part of residents' livelihood strategies. The majority of households rely on one or more members regularly travelling to central parts of the city in relation to their livelihood activities. The analysis reveals a widespread, near-to-universal, dependence on motorized transportation, with the vast majority depending on public transport. Raster-based modelling of overall accessibility provides an indication of the very high travel times endured by residents in the periphery. The analysis identifies and distinguishes between three overall mode types: 1) Private car, 2) public transport and 3) motorcycle/car combined with public transport. While private cars appear marginally faster, differences in travel times are actually limited. This suggests that travel times are less influenced by mode of transport than by road and traffic conditions and highlights how accessibility problems of peripheral settlements are not easily understood separately from the general dysfunctions of the overall mobility system of city. Keywords  Mobility  Accessibility  Urban transport  Urban expansion  Peri-urban  Cost-distance analysis