Popular transportation systems are everywhere and likely move more people worldwide than all other modes combined.

Popular transportation systems are indigenous and endemic. These systems proliferate in almost every city, town, village, and rural area of low- and middle-income countries. They also operate in the underserved fringes of high-income countries. They are so common that these systems likely move more people worldwide than all other modes combined.

Despite its ubiquity, popular transportation systems are often seen as local problems. 

The sector suffers from haphazard, discriminatory policies and regulations and little government investment. At best, popular transportation is ignored in urban transport policy and planning. More often, it is actively discriminated against. Because of this bias, the people who operate, manage, own, and invest in popular transportation are rarely consulted and are never recruited to help improve services address decarbonizing transportation. And yet, the services continue to be resilient, serving billions of people and employing millions more.