It has been often suggested that the definition of insanity is doing the same thing and expecting a different outcome. Unfortunately a dispassionate evaluation of the current state of public transit in the United States would easily fit this definition. Public transportation funding continues to require federal, state, and local tax reserves in an attempt to address the needs and adapt to the trends of growing urban communities and support sustainable mass transit solutions. Fifty years of increased funding for domestic mass transit infrastructure and services has been met with overall ridership decline (as a percentage of urban population). Caught between looming deficits and a failure to attract consumers is a mangled web of inefficient operations, financially unsustainable funding commitments, and an inability to adequately modernize transit systems. Despite good intentions, investments are now contributing to an unsustainable trend. Successful and scalable examples of ways to improve sustainability are already in place around the globe and are promoting an era of shared responsibility for mass transit between public and private sectors. Latin America, being the earliest adopter of modern and sustainable mass transit systems, operations, and infrastructure, has seen great economic and consumer success. Now other regions— China, India, South Africa, North America, and Eastern Europe—are committing to innovative and rewarding approaches to leveraging and restructuring mass transit systems. Although still a work in progress for some cities, the partnering between government infrastructure and private investors supports a future of flexibility, accountability, and profitability for mass transit in areas with growing urban populations and is a viable solution for the transportation challenges and environmental concerns associated with large populations. This report explores alternatives implemented in various countries and the factors that contributed to their successes and failures. Most successes tend to result from the collaboration itself and lead to each sector’s common triumph: government stability through a reduced dependency on public subsidies and increased private innovation. These innovative solutions for improving mass transit are sustainable and scalable and require no additional government funding or subsidies. They may be the only viable options available for creating sustainable mass transit systems.