This paper discusses the transportation challenges that urban areas in Latin America and the Caribbean face and reviews the causal evidence on the impact brought by different urban transport system interventions implemented around the world. The objective is to highlight the main lessons learned and identify knowledge gaps to guide the design and evaluation of future transport investments. The review shows that causal studies have been concentrated in certain areas and that an important number have been carried out in developed countries. Empirical challenges due to the non-random placement of these interventions and their possible effects over the entire transport network might explain the reduced amount of causal evaluations. A large part of the literature has focused on the impact of transport systems on housing values, finding overall increases in prices and rents, but with results highly dependent on the quality and perceived permanency of the system. There are few studies that explore socioeconomic effects, and those available have emphasized employment access. There are almost no studies exploring displacement effects, which should be examined to better understand the social inclusion role of transport systems. New avenues of research are emerging that exploit non-traditional sources of data, such as big data. Moreover, studies looking at ways to improve the operational efficiency of systems and those seeking to promote behavioral changes in transport users.