Many factors influence RTR. A dense city may require less transit length to provide the same level of access as a more sprawling city with the same population. Because of this, RTR is perhaps most useful for comparing transit growth over time. As populations grow, transit investment must at least keep pace with that growth and must increase faster than population growth in order to improve the ability of people to move around cities.
This map presents a baseline for countries to gauge their transit growth in the coming years. Across a diverse range of financing and development levels, countries can all make smart investments in their infrastructure, and in turn, an investment in their people.