This document proposes developing free public transport as a way to promote social justice and ecological sustainability. It discusses two alternative transportation systems - expanding private car infrastructure or improving public transit. The authors are interested in understanding projects that have implemented free public transit and their impact on society. They ask questions about who initiates such projects, their effects, costs, financing, and how they can empower social movements working for transformation. The authors believe free public transit brings together different groups to change society in a democratic, solidarity-based way and shows alternatives to current systems.