The structure of urban development in the European cities has changed its direction prior to a widespread population growth starting from the 1990s. This rapid growth taking place especially in peri-urban areas has resulted in significant consequences on the development of the urban environment. Most of the cities have experienced dispersed or scattered type of development often referred to as ‘urban sprawl’ in contrast to their more compact structures which evolved until the 1950s (EEA Report, 2006; UNFPA State of World Population Report, 2007). Transformation from compact to more dispersed structures such as ‘urban sprawl’ has significant implications. The sprawl type of development in the built-up area is generally associated with high social, economic and environmental costs. Under this situation, the concepts of urban sustainable development and urban growth management within the context of sustainability have become the focus of interest.

The main issue which has mostly attracted the attention of researchers within this field is the linkages between urban spatial structure and sustainable transport systems (Rickaby, 1987; Hillman, 1996; Breheny, 1995). Efficient mode of transportation is closely related to the urban structure since the degree of compactness and density affect the commuting distance and time, the feasibility of the main transport system, and the travel-related pollution levels. Urban theory may suggest that a compact urban form is preferred to more dispersed patterns in terms of sustainable spatial development and transportation efficiency (Hillman, 1996; Bertaud, 2004). By contrast, there are also studies questioning the sustainability of compact form (Rickaby, 1987; Breheny, 1995) and suggesting that decentralized or polycentric solutions can be as efficient.

Given this framework, this study is aimed at analyzing the impacts of Dublin’s Metro North proposal on the spatial structure of the Greater Dublin Area (GDA). The appraisal of land-use-transport relationship will be carried out through indicators and will be evaluated on two different land development scenarios carried out by the MOLAND Model: In the baseline scenario, it is assumed that there is no new rapid rail investment within the GDA while the alternative with metro scenario includes metro investment project in the north part of the Region. According to the baseline scenario, the city will continue to grow with the present trends, and presented a ‘dispersed growth’ approach compared to the more compact forms of urban development which will be achieved through the integrated land-use transportation decisions in the local and regional plans.