Kilometres-long queues formed as many vehicles crossed provinces to experience the 44.69 billion yuan (US$6.15 billion) eight-lane highway for the first time.

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Aerial view of China’s new Shenzhen-Zhongshan mega link

Aerial view of China’s new Shenzhen-Zhongshan mega link

“This proves that Chinese-style modernisation is achieved through hard work,” he added.

Xi stressed the link needed to run smoothly and intelligently to “play a pioneering role in transport and promote the integrated development of the east and west sides of the Pearl River Delta”.

He also called for more integration in the bay area, so it could become an example of high-quality development and a leading light in Chinese-style modernisation.

The bay area is Beijing’s plan to link Hong Kong, Macau and nine mainland cities to create an economic powerhouse.

Excited Hongkongers queued up at a station in Kwun Tong at 2pm to board 13 cross-border buses lined up to make the maiden trip.

A tour bus, with a Post reporter on board, crossed the Shenzhen Bay port at 3.20pm, but only made it Zhongshan at 8pm because of a traffic jam on the Guangshen Coastal Expressway, a major route connected to the project.

A check on Chinese navigation system Baidu Map at 5pm showed that the congestion along the 100km/h (62mph) expressway had slowed the estimated traffic speed on the Shenzhen side down to 12km/h.

Private vehicles with Shenzhen licence plates took up the lion’s share on the link, while some others were from neighbouring provinces and cross-border coaches.

The link will also cut journey times between Hong Kong and Zhongshan from 2½ hours to 1½ hours as coaches will no longer need to use Nansha Bridge, north of the older Humen Bridge, to reach destinations on the western side of the delta.

On Sunday, it took six hours for the tour bus to get to the destination.

Among the tour bus members was finance industry worker Jennifer Mok, 40.

She said she was excited by the prospect of a two-day trip with her husband, but the traffic jam caught her off guard.

“I expect the new bridge may be a bit busy because it is a new thing,” she added.

“But the bus was stuck on the highway for almost two hours. It’s not acceptable – and we are not even at the entrance of the link.”

Yeung Wai-hung, 62, a construction engineer, said he planned to spend the long weekend across the border with his wife and four other relatives.

He added he was not too bothered by the traffic snarl-up.

“Unexpected things happen when travelling … it’s OK as it’s the first day of the road operation,” Yeung said. “I can see ourselves travelling to Zhongshan or even more nearby cities with the link.”

A round-trip bus ticket, offered by the Eternal East Tour agency, cost HK$149 between Hong Kong and Zhongshan.

The link is designed to have a daily traffic volume of more than 100,000 vehicles.

Truck drivers who routinely travel between Zhongshan and Shenzhen told state broadcaster CCTV that they looked forward to a shorter time on the road and less cost.

One driver, Cao Lixian, said in the past he had a bed made up in the back of his truck.

He delivers cargo between Zhongshan and Yantian port in Shenzhen for his employers, who work in the export business.

“In the past, one round trip could take me at least seven hours,” he told CCTV. “I had little time to spend with my family.”

Lawmaker Ben Chan Han-pan, chairman of the Legislative Council’s transport panel, expressed concern that congestion at the Zhuhai port of the Hong Kong-Zhuhai-Macau Bridge would worsen if more drivers used the crossing under the “Northbound Travel for Hong Kong Vehicles” scheme.

He suggested that improvements be made to the road infrastructure at the Zhuhai port or consider allowing vehicles travelling back to Hong Kong to use the Shenzhen Bay checkpoint to ease the burden on southbound lanes of the bridge.

Additional reporting by Ezra Cheung and Danny Mok