The road tunnel, which forms an important part of the HK$15 billion Route 8, linking Tsing Yi and Sha Tin in the city, began construction since 2003 and was completed in 2007.

The twin tunnels are 15 metres (49 ft) wide with 12 cross-passages and emergency walkways, and a portal building at each end.

Nearly all of the 550,000 cubic metres (19,000,000 cu ft) of tunnel spoil will be reused in the Penny's Bay reclamation project or processed into aggregates at a local quarry.

[2] The contract also covered construction of tunnel control buildings and the 1.4 kilometres (0.87 mi) dual three-lane West Tsing Yi Viaduct.

COWI has provided specialist assistance to Ove Arup and Partners with the design of electrical and mechanical systems for the Nam Wan Tunnel and two adjoining viaducts.

The fans incorporated guide vanes for flow straightening to achieve maximum performance and ran at 995 RPM.