As all four main towers of the bridge are located in the water and are nearly 150 meters tall, it is extremely difficult to control the alignment. The towers are affected by strong winds, floods, and ships.

"It's more like embroidering in mid-air at a height of 100 meters," said Zhou.

The expressway starts in Qingxin district of Qingyuan, in northern Guangdong, and ends in Tanbu township of Huadu district of Guangzhou, the provincial capital.

With a length of approximately 54 kilometers, the expressway will become another major transportation artery between northern Guangdong and the Guangdong-Hong Kong-Macao Greater Bay Area.