The main artery of the 24-kilometer-long Shenzhen-Zhongshan link in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) was completed on Tuesday, marking the most significant progress before the project is scheduled to open to traffic in 2024. It is part of the world-class cross-sea infrastructure project that integrates bridges, islands, tunnels, and underwater communications. The project will connect Shenzhen and Zhongshan cities, and the provincial capital Guangzhou through the connection line.