Integrating CBA and land-use development scenarios: Evaluation of planned rail investments in the Greater Dublin Area, Ireland

Abstract

This paper evaluates key indicators of potential changes achieved by new rail investments in transportation-land-use relationships. An enhanced evaluation framework is constructed by combining land development scenarios and a cost-benefit analysis (CBA) approach to assess the impacts of potential rapid rail investments in the Greater Dublin Area (GDA). The land use development scenarios suggested in this research are a baseline business-as-usual scenario of dispersed development and two alternative with rail scenarios of more compact urban developments. In line with these scenarios, the new public transport provision of Dublin’s Metro North is evaluated on a preliminary basis considering its impacts on future land development processes in the GDA. The results obtained from the integrated CBA model demonstrate the effectiveness of an enhanced CBA approach incorporating scenarios of potential land development outcomes. The CBA approach incorporates an individual assessment of the indicators as part of the sensitivity analysis. Limitations in the methodology in terms of estimation bias, transportation modelling and the need for sensitivity analysis to be incorporated as a standard procedure in CBA are illustrated in the findings. The results of the CBA model of this study provide implications for future policy decision making and their implementation. This study contributes to constructing a framework for the evaluation of future transport policy and planning decisions concerning the GDA and other regions internationally.