The secondary section of Guangzhou Metro Line 21 (Yuancun-Zhenlongxi) was connected to the first section (Zhenlongxi-Zengcheng square) opened in 2018 and put into operation on December 20, 2019. With a mileage of 61.5km, the whole line is the longest in Guangzhou at present. It allows the top speed of up to 120km / h and the full ride takes only 53 minutes at the minimum. The connection between the east and west sections is also a milestone marking that the total mileage of Guangzhou Metro hits 500 km.

The opening of Guangzhou Metro Line 21 will further strengthen the ties between the eastern suburbs and the central urban area of Guangzhou, and accelerate the integration of the eastern suburbs into Guangdong-Hong Kong-Macao Greater Bay Area. The line offers fast and slow line operation modes. As a supplier of the signaling system, TST adopts a more flexible ATS system to strictly separate fast and slow train routings and generate scientific and optimal travel plan map to meet the operation requirements of fast and slow rides with different operating ratios at the different time during the day.

It is worth mentioning that, to facilitate scheduling and save construction costs, Guangzhou Metro Line 21 shares trains with Phase I of Guangzhou Metro Line 14 and Knowledge City extension (also equipped with the signaling system provided by TST, and put into operation in December 2018 and December 2017 respectively). Different time of construction and opening of the two lines and their large amount of data brought great difficulties to the implementation of the signaling system; TST met the hardships and successfully achieved the established objectives of the project.

TST will adhere to its original intention, and will continue to contribute to the traffic construction in Guangdong-Hong Kong-Macao Greater Bay Area with its industry-leading delivery capacity as usual. With the opening of Guangzhou Metro Line 21, the opened CBTC project of TST in China has exceeded 1000 km.