Builders labour on the Xian subway system. The OECD estimates there will be 11,000km of subways nationwide by 2030. Photo: Bloomberg

Alarms sound over local subway drive

The move is in response to Beijing's urbanisation push and part of the nation's drive to transform its economic growth model away from labour-intensive industries. But observers warn that the old malady of overinvestment may be back and could eventually lower industrial productivity, holding back Beijing's pursuit of sustainable growth.