3.3 The Corridor Development Concept
3.3.1 Definition and Emergence of Corridor Development Concept
“When man began using mechanical transportation the one-speed pedestrian city of the past changed into two-three and four speed system. From this it follows that, where in the past there was isolated settlements, there now are complex systems of transportation leading to very complex urban settlements…” (Doxiadis, 1963:117, cited in Herwin, 2005).
The quotation above illustrates the impact of vehicular transport on city form. It is not surprising then that the emergence of the corridor concept should be linked to transportation routes. According to Chapman, Pratt, Larkham and Dickens (2003) there has been a number of urban structure concepts that emerged throughout the history of planning that took the form of linear belts, which could be linked to the corridor concept. The first linear plan was envisioned in the early 1880’s by Spanish engineer Soria y Mata and addressed a regional scale linear suburban development in Madrid. This led to the formation of the Association Internationale des Cités Linéares by French planner Benoit-Lévy (Soria y Pug, 1968) which had an influence on Russian planning. The notion of outward linearity along transport routes from the city centre was developed in London in 1942.
However, in the United Kingdom (UK) linear concepts became fashionable in the development of new towns during the post war era, which took the form of circuits and double circuits. This also included development along major transport routes that spread sideways and, the grid-plan pattern, which were at an urban and sub-regional scale rather than regional, and inter-regional. The most relevant plan took place in Wales that included the stringing together of a series of villages along a new major road that ran parallel to local roads joining the main road at junctions. Hall and Ward (1998, cited in Chapman, Pratt, Larkham and Dickens, 2003) described it as the “necklace of beads approach” that influenced the recently proposed term the “string/stringing” of larger settlements along transportation corridors called sustainable development corridors. From the late 1980’s, the reformulation of the Garden City in the 21st Century found expression in the proposal of three linear cities in South East England namely; the cities of Mercia, Anglia and Kent. In order to meet increasing housing demand, the clustered development of a series of towns and villages was proposed strongly linked to strategic regional infrastructure, which facilitated the reopening of railway routes and new light rail systems.
Research findings that focused on UK’s West Midlands London corridor suggested that the primary purpose of corridors provided the means of access to a variety of different spaces and activities.
Functionally and economically, it could be seen as a dynamic space yet at the same time produced a
wide range of experiences. To the contrary, corridors of development and infrastructure may or may not serve a wide range of requirements in the same corridor and conflicts may arise between various functions. Furthermore, the European Spatial Development Perspective promoted a polycentric urban form as a means to balanced development. Within this context, “bundles of infrastructure” could be configured along the corridor identified as “braids”. This braided approach applied to lines of movement and development that reduced traffic on any single braid by providing greater access and development across a wider corridor. It was further postulated that corridors could exist as axes of:-
Infrastructure;
Economic development;
Urbanisation or
Institutional development.
All were viewed as qualitatively serving different functions that coexisted but also operating at different scales.
The research revealed that although the term corridor suggested connection and access it might not always contain all four of the above dimensions. This also implied physical and linear geographical form more than institutional structure, and homogeneity rather than distinctiveness. It was further highlighted that the fundamental characteristic of corridors was connection, and that it ought to be contained within the definition regardless of the scale of development. Corridors enabled relaxed flow or transmission of goods, people and information. It was argued that the corridor concept presented a strategy that could be used to address regional disparities, promote economic development, the protection and repair of environments. It was indicated that these performance criteria might not always be met. More importantly, the critical evaluation of the performance and functionality of heterogeneous development patterns (i.e. polycentric, monocentric, linear) against clearly defined local, regional and transitional aims and objectives was necessary.
Herwin (2005) stated that the corridor development concept, whether planned and unplanned, gained influence in spatial theory at the end of 1960’s - 1970’s. Researchers such as George R. Collins, C.F.G Whebell and Constantinos Doxiadis supported this idea. They wrote from an architectural history, geography and urban planning and design perspective on linear cities and corridor development that were directly related and could be used interchangeably. These new ideologies emerged as a cultural shift from modernism to postmodernism, an economic/technological shift from Fordism to post Fordism and post industrialism. These shifts were attributed to increase in mobility, flexibility, accessibility,
connectivity, the need for space, visibility, decentralisation and the withdrawal of government interventions which were the ingredients leading to the emergence of the contemporary unplanned corridor development.
However, in 1999, various Dutch spatial planning documents propagated planned corridor development, which then emerged as a future concept for spatial planning in the Netherlands. It was first perceived as a transport-corridor, which focused on the bundling of infrastructure, and related commercial activities within the transportation sector but included offices, research, development, and production sites. Part of the definition for corridors was presented in the “Starting Document” as “bundles of road, rail and where possible water and pipe infrastructures connected by so called multimodal change and transhipment locations” (VROM, 1999:42 cited in Harwin, 2005).
The notion of the unplanned or organic corridor development that included other activities besides transport resulted in the approach being recognised as a potential urbanisation concept. The acceptance of the idea led to the broadening of the definition as, “an urban development axis, constructed along infrastructure, composed of (existing) urban centres in combination with building zones in suburban densities between those centres intended for companies, services and dwellers”
(VROM, 1999:41 cited in Harwin, 2005). This was followed by a second part to the definition, “Corridors are intended to meet the urgent need for settlement-space of households and companies and thereby form a realizable integration-framework for the bundling of de-concentrating urban space-use.” This bundling of de-concentration was presented in a national spatial planning report, which referred to meeting the demands of population growth, and suburbanisation that occurred at appointed agglomerations along main infrastructures.
Corridor development was perceived as an inevitable and necessary phenomenon that connected main urban centres in the West of Netherlands to similar urban centres abroad such as the Ruhr Valley area in Germany and Flemish triangle in the North of France. They were recognised as an emerging network of cities to which the nodes and corridor concept was attributed. Clearly confined corridors situated along infrastructure connecting cities around greenbelts were seen as offering critical growth potential. The planned corridor consequently emerged in reaction to the unplanned corridor and urban sprawl that was widely supported and incorporated into various regional plans.
However, the lack of political support and the criticism that it would impact negatively on the economy of urban centres and urban landscapes resulted in the Compact City concept outweighing the ratification of the planned corridor. Nonetheless, the Compact City concept still encompassed the idea
of network cities within which was embedded the corridor development concept. Furthermore, the mobility of people, goods and technology resulted in urban networks that were shaped by linear (i.e.
corridors) and nodal (i.e. nodes) urban development. By the end of 1990’s, the Dutch discussion on corridors presented it as an actual spatial development concept that could be complementary to existing urban nodes. Corridor development was not just regarded as a Dutch concept but was promoted as a spatial planning strategy in Europe, UK and Germany. However, confusion around whether it should be regarded as an urban development axis, infrastructural axis, economic development axis and issues surrounding scale levels were debated.
Khoza and Willemse (2013) have argued that the term “corridor development” can be used interchangeably with many other terms such as “development axes, connecting axes, concentration axes, urban axes, growth axes, development lines, growth axes, ribbon development or development spines” (Geyer, 1989 and Potter, 1963). Moreover, the term “development centres” referred to towns and cities located along or on either side of development corridors/axis, which serve as centres that activate social and economic activities. Other terms that can be used to describe development centres included “development nodes, growth centres, growth poles or core regions”. According to Friemann (1966, cited in Khoza and Willemse, 2013), development axis (i.e. corridors) connect two or more development centres (i.e. nodes). The spatial and functional organisation of regions occurs along corridors that comprise of an agglomeration of nodes (i.e. development centres). Recent studies have made use of the term “development corridors” that refer to bundles of infrastructure (highways, rail links, bus lanes, cycle paths, air connections, sea canals) that link two or more urban areas. Marriam and Freeman (2001, cited in Khoza and Willemse, 2013) defined corridor as “a linear spatial element consisting of two outer nodes and strips and/or inner nodes of high intensity non-residential and/or high density residential land use that are connected by at least one mass public transport route which may be fed by supporting feeder routes.”
The South African National Department of Transport have defined corridors as “high volume transport routes that link major urban centres that are highly concentrated with passenger and freight movement”. The Cape Metropolitan Council (1996:43) illustrated the concept of development corridors as a string of beads which refers to corridors that connect a series of nodes where centres/nodes and sub-centres/sub-nodes are located along the main movement channel that generate high levels and densities of development as depicted in Figure 20 below. They support the principles of urban integration, intensification and containment of urban sprawl to facilitate the creation of quality urban environments. In order for corridors to function, optimally some of the critical elements needed
include; public transport, major transportation routes, human interaction, linkages between nodes and sub-nodes, available services and public investments.
Figure 20: String of Beads Concept
Source Cape Metropolitan Council, 1996
Certain preconditions are required in order for corridor development to occur and these include economic, political, institutional, physical, planning, transport, behavioural and perceptual. Meyer and Oranje (2001, cited in Khoza and Willemse, 2013) present a structure that described the phases of corridor development and the generic components. Initially corridors require forces of attraction.
These forces stimulate the movement of people and activities between the two outer most nodes/centres of the corridor, the inner nodes/centres between the two outer nodes, and the land area running directly alongside the corridor and between the inner and outer nodes. The inner and outer nodes act as attractors or senders of people, or activities or both. Therefore, the main purpose of the corridor is to convert senders to attractors in the form of investors and incentive schemes.