大興区
Line BRT 1 opened on December 30, 2005 and is one of China's first BRT lines. The line heads south from Qianmen to Demaozhuang (in Daxing District) in the south and is about 16 km long with 17 stations. It runs on bus lanes in the center of the road. All stations on the line are island platforms so specially designed buses with doors on the left are used on the line. It is the only route to use left-door buses. In 2009, it had an average daily ridership of 150,000 passengers. In 2015, the line was upgraded to use trolleybuses.