There is a long history of the study of interdependence between transport and development. On the one hand transport points with initial favorable advantages can be drivers of growing economic activity. The development of the system after that is likely to be guided by the goal of linking the areas with the greatest development. (See Taaffe/Morrill/Gould for an idealized typical sequence of development.) I have thought a good deal about this problem and there are more nuanced and elaborate ideas at the heart of your question. On the other hand, a lot of this thinking has a bias towards growth and "more is better." This idea is not without its problematic aspects.

Building a transport corridor and expecting that development will automatically follow is probably not going to be the way it works. Much more likely is that the transport corridor linking places CAN possibly become the nexus of a set of advantages in terms of accessibility that will lead to further positive feedback (also known as “circular and cumulative causation”). One of my favorite versions of this is the work of Friedman and in some ways Hirschman where the complex concepts of spread and back wash and spillovers point to the idea that a transport advantage can lead to more positive effects (in terms of further locations and clusters). Now, one of the surest ways to have a growth corridor is to have a link that connects large nodes which themselves are active points of production and consumption. Friedman I think coined the idea that growth is focused on corridors linking places that are a highly interactive. In some ways the push into the ex-urbs beyond the circumferential highways that ring US cities occur along roads leading to other centers. One can also see the effect of attempting to “bundle” and market regional economic access as an asset as in say the areas of North and South Carolina in the US.

I am leaving aside for others the more critical issue of whether a corridor with concentrated growth and development can actually have some negative consequences for the indigenous forms of crop production and economic land use in developing regions.

Thanks for the provocative question, and I look forward to other replies

There are of course several types of transport and development corridors. They may have a particular logic and impact in Africa. My study, with Ian Taylor, of the ‘flagship’ of the South African Spatial Development Initiative (SDI) programme, the Maputo Development Corridor (MDC), shows that MDC reinforces the role of the state as a transmission belt for transnational capital, rather than as a facilitator for ‘development’.

For instance, the neo-liberal market fundamentalism and big-bang approach inherent in the MDC spells ‘jobless growth’ and that the state is very much reduced to an ‘investment promotion agency’. But even if the MDC and several similar development corridors and SDIs are problematic, it is still possible to turn these ventures into something potentially good by having a heavier focus on ‘development’, through a more pro-active role for national and local government, and more comprehensive and inclusive governance structures (see Regionalism and Uneven Development in Southern Africa. The Case of the Maputo Development Corridor, Ashgate 2003).

Other types of transport corridors are sometimes more heavily focused on removing trade-related bottle-necks or building trade-related infrastructure (especially at border crossings). Such projects may be of relevance both for both big and small business and trade, and the donors and the African Development Bank tend to believe in them. Yet, the positive impact on development and poverty reduction is far from clear.

No doubt about transportation corridor but feeder to this corridor is equally important for well developed network apart from that cost benefit analysis. So it is best only when it is integrated. not in isolation .  

Thank you all for the insights. Fredrik Soderbaum, am particularly interested with the regional effects of MDC and how it can be a Case to other regional-based Spatial Initiatives because i tend to think its the most successful SDI within the Southern African context if not the whole of Africa. But as you say its indeed complex and more research has to be done to ascertain its impact in the developing states.    

To increase the flows between urban and rural sub-regions, transport corridors can play an inevitable role. However, one must not forget the other credential elements of regional development, i.e. growth pole, economic base or central place, etc. Road connectivity and low-cost transport facilities certainly can provide opportunities to rural households and increase their accessibility criterion.