Major public events, such as sporting events, carnivals and festivals, are common occurrences in urban and city environments. They are characterised by the mass movement of people in relatively small areas, far in excess of normal daily activity. This section reviews how different metro systems across the globe respond to such peaks of activity, ensuring that people are moved swiftly, efficiently and safely. To this end, representatives from four major public metro systems (London, Hong Kong, Rio de Janeiro and São Paulo) describe how their respective metro systems respond to the capacity demands of a major annual event.