The impact(s) of enclosed neighbourhoods on transport patterns within the City of Tshwane

Abstract

The occurrence of enclosed neighbourhoods has become a common phenomenon in South African cities from the early 1990’s as a direct impact of crime rates and the fear of crime. While the enclosure of neighbourhoods provide an immediate (temporary) solution to combatting crime within existing neighbourhoods, a number of (unintentional) socio-physical and spatial consequences occur. Numerous research have been done to establish the social implications of enclosed neighbourhoods in South African cities, including the City of Tshwane, while very little research have been done to establish the physical impacts of enclosed neighbourhoods on the urban form, its impact on the transport patterns or travel behaviour and consequently the increased greenhouse gas levels being emitted into the atmosphere. This study establishes the occurrence and extent of enclosed neighbourhoods within the City of Tshwane to create a generic classification system to establish the practical impact of enclosed neighbourhoods on urban form. In-depth case studies into two enclosed neighbourhoods and a neighbourhood located adjacent to an enclosed neighbourhood were conducted to examine the impact(s) of these neighbourhoods on transport patterns, travel behaviour and greenhouse gas emissions. An overview of movement networks and an investigation of the influence of the built environment versus self-selection were launched to gain insight into the different factors that might contribute to travel behaviour in general, in addition to neighbourhood enclosures and neighbourhood re-design. This brought forth the very important relationship between land use management, transport planning and the different governing bodies and policies. The ultimate results gained from the study of selected neighbourhoods clearly showed that a number of factors influence individual transport patterns and travel behaviour, such as self-selection, initial neighbourhood design and population growth. The study did however reveal that through enclosing neighbourhoods and altering its initial neighbourhood design and movement networks, travel behaviour, transport patterns and inevitably greenhouse gas emissions for the specific neighbourhoods and adjacent neighbourhoods will unavoidably change and thus impact negatively (in some ways) on the urban form. More specifically, the results gained from this study showed that those residing within and adjacent to enclosed neighbourhoods travel greater distances on an average day, compared to those who live in an ‘open’ neighbourhood. Consequently, the average household residing within an enclosed neighbourhood emit on average up to (approximately) 4600 g/km CO2 per day more than households residing in ‘open’ neighbourhoods, which result in enclosed neighbourhoods emitting up to 26% more CO2 than ‘open’ neighbourhoods. Despite these results, residents of these enclosed neighbourhoods believe that the enclosure of these once ‘open’ neighbourhoods do not affect their travel behaviour or any traffic congestion and proclaim that their number one priority is safety which they believe is achieved through the enclosure.