Moving from plan to action seems a trivial affair. However, when vast resources are mobilised to deliver the transformation to sustainable mobility this is not so trivial. The Government of the Republic of Ireland is currently investing around €165 billion for infrastructure development over the next 10 years, with more than 20 percent allocated to the transport sector. Key policies provide the ambition and direction for such mobilisation: the National Sustainable Mobility policy (NSMP) and the National Investment Framework for Transport in Ireland (NIFTI). In addition the Infrastructure Guidelines (IG) provides the rules of approvals in the public sector to ensure value for money. From all this, a number of programmes and projects to deliver such policies emerged, such as BusConnects, Metrolink, DART+, and Active Travel programme to name a few. This paper delves into the literature of project management and institutional economics, and presents the case study of the National Transport Authority in Ireland to assess determinants affecting the degree of effectiveness in its delivery. Using an adapted PESTEL analysis, we conducted interviews to selected experts to determine the likelihood of such determinants. Lessons learned offer insights to policy makers and managers of public transport programmes elsewhere.