Spectacular photos of the world's longest sea bridge

The Hong Kong-Zhuhai-Macau Bridge connects mainland China with the semi-autonomous territories of Hong Kong and Macau, measuring a whopping 55 kilometre. The bridge encompasses 11 cities, including Hong Kong and Macau, that are home to a combined 68 million people. Photograph: Bobby Yip/Reuters

The bridge took nine years to complete and spans the waters of the Pearl River Estuary. It will cut the travel time between Hong Kong and Zhuhai from three hours to 30 minutes. On Tuesday, Chinese President Xi Jinping inaugurated the construction, saying, “I declare the Hong Kong -- Macau -- Zhuhai bridge officially open.” Photograph: Aly Song/Reuters

The bridge was first proposed in the late 1980s by Gordon Wu Ying-sheung, a businessman from Hong Kong. He was a strong advocate of creating an advanced transport system in the Pearl River Delta area. However, the idea of a mega bridge was opposed at the time by Hong Kong’s British colonial government, which was wary of development that might draw the city closer to Communist China. China expressed support for the project in 2003, and construction began in 2009. Photograph: Aly Song/Reuters

Once it opens to the public on Wednesday, regular motorists, won’t be able to drive across it -- a special permit is required. According to CNN, most drivers will have to park and then switch to a shuttle bus or specially hired car to go across. Tolls will range from 60 yuan to 300 yuan (Rs 300 to Rs 3,000), according to China Daily. Photograph: Bobby Yip/Reuters

Once the bridge opens, it will be complicated to drive across the bridge. In Hong Kong and Macau, drivers travel on the left side of the road while in China, they travel on the right. To get around the issue, reports said authorities built a "merge point" for drivers to stop and switch sides when they cross into new territory. Photograph: Bobby Yip/Reuters

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. Photograph: James Pomfret/Reuters

According to reports, the amount of steel used in this bridge is enough to build 60 Eiffel Towers and the bridge itself is 20 times longer than the Golden Gate Bridge in San Francisco, USA. Photograph: James Pomfret/Reuters

The bridge includes a 6.7-kilometre 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 metres and situated in relatively shallow waters. Photograph: Bobby Yip/Reuters

Special cameras will be on the look-out for drivers on the bridge who show signs of getting sleepy, among other checks -- yawn three times and the authorities will be alerted, local media report. To help counter potential terror attacks, there will also be “48 high-definition surveillance cameras” mounted at intervals along the bridge as well as anti-terror police patrols, the South China Morning Post reports. Photograph: Bobby Yip/Reuters

Originally slated to open in 2016, the bridge has been dogged by construction delays, budget overruns, and safety issues. Nine workers have died and more than 200 others have been injured building the bridge. This year, six subcontractors have been fined for endangering workers. Photograph: Bobby Yip/Reuters

The bridge isn’t without criticism. Environmental groups say the project may have caused serious harm to marine life in the area, including the critically rare Chinese white dolphin. The number of dolphins seen in Hong Kong waters has decreased from 148 to 47 in the past 10 years and they are now absent from the waters near the bridge, according to the Hong Kong branch of the World Wide Fund for Nature. Photograph: Bobby Yip/Reuters

Critics of the Chinese government also say that the bridge is a tool to drag the Hong Kong closer into Beijing’s grip. Photograph: Aly Song/Reuters

The bridge, surrounding link roads and artificial islands cost a staggering $20bn to build - the main bridge alone cost $6.92bn. Chinese officials say it will generate up to 10 trillion yuan ($1.44tn) for the economy. According to an estimate by BBC Chinese, the bridge will only earn around $86m in tolls per year. In fact, the bridge's maintenance costs would already take away a third of this income. Photograph: Aly Song/Reuters

This is another feather in the cap for Chinese authorities, who lay claim to the record for the world's longest bridge of any kind - the Danyang-Kunshan Grand Bridge, a viaduct (168 km-long) which is part of a high-speed rail line. Photograph: Bobby Yip/Reuters