Train departures, door opening and closing, and all operations will be fully automatic, using only domestic technology.

China began developing its own automatic metro operation system in 2010 and says core technology is now ready.

Beijing metro lines 3, 12, 17, 19 and the new airport line will all operate with completely automated, driverless trains once planning has been finalised.

The total length of fully-automated subway lines in Beijing is forecast to reach 300km by 2020.