28 December 2021. Line 20 runs at the same top speed as line 11, at . The line is operated by SZMC (Shenzhen Metro Group). Line 20's color is light blue. 28 December 2021: Airport North – Convention & Exhibition City History Early planning In late 1983, Party Secretary of Shenzhen Mayor Liang Xiang led a team to Singapore to study its mass transit system. Upon returning it was decided that on each side of Shennan Avenue should be protected as a green belt, and to set aside a wide median reserved for a light rail or light metro line. In 1984, the "Shenzhen Special Economic Zone Master Plan (1985–2000)" pointed out that, with the growing population and traffic in Shenzhen, a light metro system would not have sufficient capacity to meet future demand. Instead the report proposed a heavy rail subway line to be built along Shennan Avenue. The project was finally approved by the Central Planning Department in 1992. In August 1992, during and re-feasibility and rail network planning, The Shenzhen Municipal Government decided to move from building a light metro line to a heavy rail subway line. The rapid growth of Shenzhen City made a lower capacity light metro line impractical. In 1994, Shenzhen organized the preparation of the "Shenzhen urban rail network master plan" to be incorporated into the "Shenzhen City Master Plan (1996–2010)". The city's vision for an urban rail network would consists of nine lines. Of the nine transit lines, three of them would be commuter rail lines upgraded from existing national mainline railways. The total length of the proposed network would be about . The three upgraded commuter rail lines would overlap the Guangzhou–Shenzhen railway, Pinghu–Nanshan railway and Pingyan railway. This plan established the basic framework for the Shenzhen Metro network. Construction suspended and restarted In December 1995, the State Council issued the "moratorium on approval of urban rapid transit projects" to suspend approval of rail transit projects in all Chinese cities except Beijing, Shanghai, and Guangzhou. The Shenzhen Metro project was postponed. In 1996, prior to the handover of Hong Kong, authorities attempted to restart construction by renaming the project "The Luohu, Huanggang / Lok Ma Chau border crossing passenger rail connection project", stressing that the project is designed to meet the potential growing demand for cross-border passenger traffic after the handover. In 1997, Shenzhen reapplied its Subway plans to the State