The "Signal Shala", or traffic signal school, caters to dozens of children who have been left out of the formal education system. MUMBAI: Beneath a busy flyover in India's financial capital Mumbai, a row of pastel-coloured shipping containers houses an unlikely school serving some of the city's most marginalised children. Despite laws guaranteeing free schooling for children aged six to 14, poverty and migration continue to keep many out of classrooms, particularly in sprawling cities like