Chinese President Xi Jinping officially opened the world's longest sea-crossing bridge Tuesday at a ceremony in the southern city of Zhuhai.
The $20 billion megaproject further connects mainland China with the semi-autonomous territories of Hong Kong and Macau, with a 55-kilometer (34-mile) road bridge that has been in the works for almost nine years.
It's a key element of China's plan for a Greater Bay Area covering 56,500 square kilometers (21,800 square miles) of southern China, and encompassing 11 cities, including Hong Kong and Macau, that are home to a combined 68 million people.
"I declare the Hong Kong -- Macau -- Zhuhai bridge officially open," Xi said in a seconds-long speech before a giant display showing the bridge.
The announcement was greeted with applause from the hundreds of guests in attendance, including the leaders of Hong Kong and Macau, Carrie Lam and Fernando Chui, and Guangdong Party Secretary Li Xi.
The bridge will open to the public for the first time on Wednesday.
Greater transport links
Proponents of the bridge say it will significantly cut journey times between the cities, enabling commuters and tourists to easily move around the region.
"With the bridge, the traveling time between Hong Kong and the Western Pearl River Delta region will be shortened significantly, thereby bringing the Western Pearl River Delta region within three hours' drive from Hong Kong," the city's transport secretary, Frank Chan, said Friday.
Despite the focus on drive time however, private car owners in Hong Kong will not be able to cross the bridge without a special permit. Most drivers will have to park at the Hong Kong port, switching to a shuttle bus or special hire cars once they are through immigration. Shuttle buses cost $8 to $10 for a single trip depending on the time of day.
Critics however point to limited demand in Hong Kong for the project, and competition from improved rail links and the Shenzhen-Zhongshan bridge, which once completed around 2024 is expected to cut traffic on the Zhuhai link by over 25% within 20 years.
For critics of the Chinese government, the bridge is seen as a tool to drag Hong Kong -- which boasts a semi-democratic legislature and independent judiciary -- closer into Beijing's grip.
"You can't see the existing transport connections -- in a literal way. But this bridge is very visible ... you can see it from the plane when you fly in to Hong Kong, and it's breathtaking," lawmaker Claudia Mo told CNN earlier in the year.
"It links Hong Kong to China almost like an umbilical cord. You see it, and you know you're linked up to the motherland."
Huge engineering effort
Built to withstand a magnitude 8 earthquake, a super typhoon and strikes by super-sized cargo vessels, the bridge incorporates 400,000 tons of steel -- 4.5 times the amount in San Francisco's Golden Gate Bridge.
It also includes a 6.7-kilometer (4-mile) submerged tunnel to help it avoid the busy shipping paths over the Pearl River Delta. The tunnel runs between two artificial islands, each measuring 100,000 square meters (1 million square feet) and situated in relatively shallow waters.
While an impressive engineering feat, the building of the bridge brought its own controversies. The Pearl River Delta is home to an endangered Chinese white dolphin population that has been buffeted by massive land reclamation efforts in Hong Kong and other cities.
Conservation experts previously told CNN they feared the bridge, as well as ongoing expansion of Hong Kong airport, could be the final nail in the dolphins' coffin, sending the local population into terminal decline.