produced confirmed that environments located alongside main transport routes in the city of Cape Town that grew in an evolutionary or organic manner performed better as compared to consciously planned urban development. More importantly, this contributed to integration, convenience and accessibility of services and facilities to communities, which in response stimulated the increase in thresholds and economic benefits. The corridor concept was therefore further refined. It was argued that the creation of an interlocking, reinforcing, hierarchical network of spines that allowed the intensification of activities to be located in direct relation to major movement routes interconnected many local areas and presented a number of advantages.
Dewar (1984, cited in Martens, 2001) argued that these advantages included the integration of the city;
accessibility to a wider range of opportunities; generation of thresholds for a range of activities; small businesses could benefit by locating closer to higher order facilities amongst others. Hence, the corridor concept gained credence. It has since become linked to the broader agenda of transformation of South African cities. A report prepared by Council for Scientific and Industrial Research (CSIR) also stated that the corridor concept constituted a critical structuring element which could be used to improve access of opportunities to poor, low-income townships and promote economic growth through improved access.
It was also evident that the concept was readily accepted by planning practitioners, academics and the government who recognised the need to promote the integration between land use and transport planning. The corridor concept has since remained an important planning instrument, which was incorporated into various pieces of legislation, and policy documents that provided guidelines and directives towards the restructuring of cities that will be tabulated and discussed in the sections following hereunder.
Donaldson (2006) indicated that the integration between transport and land use planning play a crucial role in the reshaping of urban form. As such, the notion of development corridors is said to connect major nodes to create purposeful interaction and would therefore require high-density development that incorporates residential and commercial development along transport routes. Brand and Geyer (2015) further reiterated that development corridors are the outcome of interaction between development centres (i.e. nodes). The corridor concept is an important tool in planning and geography where nodes play a dominant role in that it is they are a determinant factor in the establishment of corridors. The flow of goods and information between such centres (i.e. nodes) create favourable conditions to promote further urban development. Various nodes form a unique flexible exchange environment allowing for dynamic synergies of interactive growth to achieve scope of economies aided by fast and reliable corridors. Studies have proven that in South Africa, nodes do play a significant role
in the establishment of development corridors. It is a planning tool that can facilitate spatial, economic, social integration; and the restructuring of Apartheid cities in an optimal manner.
Of significance is the concentration of activities within dominant nodes. The emergence of a multimodal structure and the flows of economic activities between nodes results in the creation of development corridors that channel and focus economic growth between a networks of cities. These outcomes endorse the spatial and economic role of corridors as development instruments. In South Africa the four dominant nodes identified represent city regions namely; Tshwane, Johannesburg (as part of Gauteng), Cape Town and eThekwini. These centres are located in defined metropolitan areas and serve as prominent nodes. They exert great forces of attraction for the distribution of development, economic growth and migration. In addition, research findings have shown that the concept of a network of cities provides opportunities for diversity, creativity and greater freedom in locational choice and creates new opportunities for economic agglomeration and growth. It has been pointed out that the strength of corridors responded to distances of nodal areas from each other and that poly- centralisms led to stronger corridors.
The Cape Town Spatial Development Framework (2012) described development corridors as broad linear areas of high-density development centred on activities and development routes characterised by dynamic, mutually supporting relationships between land uses and movement systems. More importantly, facilitating the access and integration of communities to service provision, economic and social opportunities and are regarded as a combination of strip development that comprise mixed uses (i.e. residential, commercial and industrial) located along portions of corridors and nodal development comprising of clustering of activities at points of maximum accessibility. As a result, corridors require vibrant functionally interdependent nodes that generate high levels of interaction in order to function efficiently.
As demonstrated above the corridor concept plays a critical role as a primary restructuring element within the South African context. In 1994, the new democratic government recognised the urban challenges it had inherited and recognised the need for urban planning (i.e. land uses) and transport planning to be integrated. Therefore, new concepts such as corridors and nodes were introduced in a number of plans, policies and legislative documents that have fundamentally changed the planning system in South Africa in order to create an enabling framework for implementation. Hence, some of the key principles that underpinned the legislative framework were informed by the need for greater
integration in contrast to separation, compaction as opposed to sprawl, sustainability as opposed to inefficiency and equity as opposed to inequality.