The 12km long Incheon bridge is selected as one of the world's construction wonders

South Korea has opened a huge bridge spanning between Yeongjong island and the Incheon Metropolitan City, southwest of Seoul.

The Incheon bridge is 12km long making it the longest spanning cable-stay bridge in Korea and the seventh largest bridge in the world.

It connects the Songdo International Business District in the Incheon Free Economic Zone (IFEZ) to Yeongjongdo, where Incheon International Airport is located.

The project began in 2005 and was completed in time and on budget, according to the developers. It is anticipated that the $1.4bn project to build the bridge will significantly relieve traffic congestion in the city.

Motorists will now be able to reach the airport from Songdo in about 20 minutes, cutting the previous travel time by two thirds.

A team of risk engineers from Allianz Global Corporate & Specialty provided risk consulting on the project.

The biggest risks to the project, said Allianz, were natural hazards like tsunamis, plant and equipment failure during the heavy lifting of bridge components, and quality issues in the construction of the bridge elements.

The UK's Construction News selected the bridge as one of the world's 10 construction wonders.

A consortium between AMEC and Incheon City managed the project.