The three entirely-underground lines new comprise lines 3, 12 and 17. Line 3 will be 22km long with 14 stations and will connect the Dongcheng and Chaoyang districts with Dongba and Shifoying in the east.\r\nLine 12 will serve the northern part of Beijing and will run east-west. This 29.6km line will have 20 stations and is designed to relieve congestion on Beijing's North Third Ring Road. It will link Century City, Shuangyushu, Great Bell Temple, Madian, Jiuxianqiao, and Dongba.\r\nLine 17 will be a north-south express metro with a design speed of 100km\/h. The line will connect four districts in the east of the Chinese capital: Tongzhou, Dongcheng, Chaoyang and Changping, and is designed to support some new developments. This 49.7km line will also have 20 stations.\r\nThe Fangshan Line will be extended 5.2km north to Fengtai railway station where it will connect with lines 10 and 16, while the Airport Express Line will be extended 1.9km west from its current terminus at Dongzhimen to Beixinqiao to connect with Line 5.\r\nThe Beijing Metro currently has 18 lines totalling 527km with 320 stations and it carries around 10 million passengers per day.