By comparing two transportation plans, one implemented and the other forgotten on a bookshelf, the case of Bogota, Colombia, offers the opportunity to understand the determinants underlying effective plan implementation. Results suggest that a plan will be implemented if the planning process is politically and financially realistic. These two initial characteristics should be self-evident, because without adequate funding or political conditions, no policy can be implemented. The analysis highlights the importance of two additional factors for successful project implementation: the existence of a minimum level of institutional capacity, and that the overall planning and implementation exercise is driven by the desire to implement the project.