It is also second in the world in overall length, with the Lake Pontchartrain Causeway in the United States being 2.8 kilometers longer. Construction of the bridge was completed on June 14, 2007, and an opening ceremony was held on June 26, 2007 to great domestic media fanfare. But the bridge was not opened to public use until May 1, 2008 after a considerable period of testing and evaluation.The bridge shortened the highway travel distance between Ningbo and Shanghai from 400 km (249 mi) to 280 km (174 mi) and reduced travel time from 4 to 2.5 hours.
This video from Discovery Channel shows how the bridge was designed and made. Quite impressive. Hope you like it.