3. Nov 15: Overpass bridge replaced in 43 hours

Beijing has replaced the old part of an overpass bridge after years of use wore out parts of Sanyuan Bridge on the northeastern 3rd Ring, where one of the city's heaviest traffic volumes is found, in just 43 hours.

It was the first time China had replaced a vital traffic bridge in such a short time. Workers restored the Sanyuanqiao junction, a major congestion point on a toll way to the airport. It also links two pivotal highways: the 3rd Ring Road and the highway linking downtown Beijing with the outlying Shunyi District.

Workers used global positioning systems, lasers and robots to replace old sections with prefabricated steel structures. The most challenging part of the overhaul was the replacement of the 1,300-ton bridge structure, which cost 39 million yuan ($6.1 million), according to Xinhua.

The process started at 11 pm on Nov 13 and was complete by 6 pm on Nov 15 with traffic returning to normal immediately.

A time-lapse video on YouTube and other websites wowed people domestically and internationally.

An internet user @wmh in the UK commented: "It took my local council over two weeks to take care of a blocked sewer." Another user @plorf said: "Pretty impressive I must say. Neat job".

New bridge sections are moved into position at Beijing's Sanyuanqiao junction on Sunday, Nov 15, 2015. [Photo/China Daily]