Trans-boundary highways have increasingly complemented trade agreements as instruments of global economic integration, and both have incurred political protest. This article presents a comparative analysis of two recently proposed trans-boundary highway projects, the Trans-Texas Corridor from Mexico through Texas to Oklahoma in the USA, and the Inter-Oceanic Highway in the southwestern Amazon where Bolivia, Brazil and Peru meet. The analysis focuses on the similar political contexts, justifications and funding models, as well as the contrasting political responses and implementation outcomes. The findings reveal important differences in the two cases, even among their ostensibly similar aspects, which are necessary to provide an adequate explanation as to why social mobilization stopped one project but not the other. The analysis bears implications for the social-political study of trans-boundary infrastructure as an instrument of economic globalization.