southern arc of the Loop line across the Yangtze River using a long suspension main span, making it the longest metro-only suspension bridge by main span in the world. The Nanjimen Bridge will carry Line 10 trains across a cable-stayed bridge with a main span of , making it the longest metro-only cable-stayed bridge by main span in the world. The Gaojia Huayuan Jialing River Rail Transit Bridge carries the western arc of the Loop line over the Jialing River using a long bridge with a main span of . Finally, the Chongqing Rail Transit has numerous double-deck bridges carrying vehicle and metro traffic, such as the Chaotianmen Bridge, which is the world's longest arch bridge. Network Loop line The Loop line (coded as "Line 0") is a rapid transit loop line. The northeastern section was opened on 28 December 2018. The southern section with the Egongyan Rail Transit Bridge opened on 30 December 2019. Three major railway stations in Chongqing are also linked by this line: Chongqing North railway station, Shapingba railway station, and Chongqing West railway station. Loop Line's color is yellow. Line 1 Line 1 runs from Chaotianmen, in the central west, to Shapingba and then to Bishan with a total length of . It is the first heavy-rail subway line in Chongqing and the second in Western China. The passenger capacity is 36,000 passengers per hour in each way. The line serves as the system's backbone connecting the densest areas including the main Central Business Districts of Jiefangbei, Lianglukou, Daping, and Shapingba. It is the first conventional subway, running in a deep-bored tunnel below Yuzhong and Shapingba Districts. Line 1 has transfer interchange stations with Line 6 at Xiaoshizi and Line 2 at Jiaochangkou in Jiefangbei CBD and at Daping and Line 3 at Lianglukou, which is near Chongqing railway station in central Yuzhong. Line 1 is also transferable with the Loop Line at Shapingba, although out-of-station transfer is currently needed due to construction setbacks on the interchange channel and concourse connecting the two subway lines. In 1992, the Chongqing government signed a Build-Operate-Transfer agreement with a Hong Kong company and provided the land for the project, but work ceased in 1997 because of legal issues. Work resumed from Chaotianmen to Shapingba on 9 June 2009, and a limited opening occurred on 28 July 2011. Thales provided an operations control centre for the line. Line 1's