Resumen
When public authorities face the need to improve a transportation system, they normally have to make a difficult choice among a set of technological and operational alternatives. To help the correct evaluation of each alternative and its impacts, costs and benefits, it would be useful to have a decision support tool based on approaches such as Multi-Criteria Decision Analysis (MCDA) and/or Cost-Benefit Analysis (CBA). Among the many impacts caused by a public transportation system, typically those on the land use are not adequately considered in the decision-making processes, mainly because they are hard to monetize, they are often considered as value transfer instead of value creation, and they are too complex to be assessed by traditional transport modelling tools. To overcome these weaknesses, the objectives of this research are to identify and measure the impacts of transit systems on land use and accessibility, and to consider those impacts in decision-making processes, along with more traditional financial and transport related impacts. For this purpose, a decision support tool, combining a land use and transport model with a MCDA model, was developed and assessed in a small case study. In future work, sensitivity and risk analysis will be incorporated, to more accurately and realistically reflect uncertainties and exogenous conditions that may significantly affect the costs and the benefits of a project. Finally, this decision support tool will be fully assessed in a study of the Green Line extension project in Boston, USA.