The Philippines has long faced profound challenges in modernizing its urban transport infrastructure. Its capital region, Metro Manila, struggles with chronic congestion and connectivity woes, stunting economic growth and quality of life. This chapter investigates the institutional dynamics of Official Development Assistance (ODA) and Public–Private Partnership (PPP) as financing modalities for railway projects in Metro Manila, focusing on four ongoing railway projects—two funded via ODA (Metro Manila Subway Project and North–South Commuter Railway Phase 1) and two funded via PPP (MRT-7 and Makati Intra-city Subway). This chapter employs rational choice institutionalism to analyze the behavior of key actors and the institutional frameworks that influence project outcomes, arguing that the design and implementation of these projects reflect the character and capacity of the Philippines’ formal and informal institutions in these two starkly different modalities. Findings suggest that ODA projects benefit from transparency-driven governance reforms and adherence to international best practices, thereby enhancing sustainability and fostering stakeholder trust. Conversely, PPP projects face governance challenges linked to confidentiality norms, which prioritize competitiveness over public accountability and comprehensive evaluation. Policymakers must craft and implement reforms to achieve sustainable urban transport development in Metro Manila, utilizing ODA and PPP financing modalities. This involves enhancing PPP regulations to reconcile public interest and competitiveness concerns, harnessing ODA for capacity building and institutional reform and exploring innovative financing mechanisms, such as hybrid ODA-PPP models. These approaches enable the Philippines to optimize rail transport financing, improve urban connectivity, and promote environmental sustainability, spatial equity, and long-term social cohesion.