An aerial view of the Hong Kong-Zhuhai-Macao Bridge. At 55 kilometers, the bridge is the world's longest sea-spanning structure. [Photo/HZMB AUTHORITY]

The Macao border zone of Hong Kong-Zhuhai-Macao Bridge (HZMB), the world's longest cross-sea bridge, was put into use as the bridge opened to public traffic on Wednesday morning.

The 55 km-long bridge links China's Hong Kong Special Administrative Region (SAR), Zhuhai City of Guangdong Province and Macao SAR.

The Macao border zone covers an area of 71.6 hectares, including a six-floor building for customs clearance, two public car parking lots with more than 6,000 slots for private vehicles and another 2,000 for motorcycles, municipal facilities as well as the road network, tunnels and flyovers.

The Macao border zone officially opened at 9:00 a.m. local time (0100 GMT). The passengers went to the departure hall, and passed through the boundary checkpoints via automatic or manned channels. They bought tickets for shuttle buses from Macao to Hong Kong, with cash or by Alipay.

At 9:20 a.m. local time (0120 GMT), the first shuttle bus from Macao to Hong Kong left the the Macao border zone.

Cross-border services for passengers and vehicles travelling between Macao and Hong Kong are available 24 hours a day.

Meanwhile, passengers going to Zhuhai can use the brand-new "Joint Inspection and One-time Release" channel to pass through the check points.

The Macao border zone of HZMB was completed on Dec. 18, 2017.