Subway systems from Shanghai and Dubai to Paris have installed safety doors over the last three decades.

WSJ: NYC subway safety options discussed

In the 15 years Dodington has lived in Shanghai, the city's subway system went from nonexistent to the world's longest network with 420 kilometers (260 miles) of tracks.

CNN: Americans fall for rising Shanghai

This month TDSi won a contract to make control equipment, readers and software for 12 subway stations in Beijing, having already supplied kit for metro systems in Shanghai and Tianjin.

ECONOMIST: Manufacturing and exports