India, Dec. 31 -- Every morning in India's megacities, commuters can be seen jostling for space on overcrowded buses or haggling with auto drivers who quote fares on a whim. For most office-goers, options are limited -- stand in endless queues for a bus or open a ride-hailing app and brace for surge pricing and cancellations, or both.

This daily grind captures India's continuing urban transport crisis. Despite years of policies and plans, public transport in most cities remains inadequate and overburdened. Buses-the backbone of urban mobility-are in short supply. Metros have grown fast in some cities, but they only cover certain corridors and can't handle last-mile trips or spread-out journeys.

Into this chaos comes what many see as an ...