Oujiang North Estuary Bridge, Multi-level bridge in Wenzhou, China

The Oujiang North Estuary Bridge is a multi-level structure that crosses the Oujiang River with separate lanes designed to handle different types of traffic simultaneously. It connects mainland Wenzhou to nearby islands and supports both daily commuting and commercial transport.

Construction of the Oujiang Beikou Bridge began on 30 November 2016, and the main bridge was joined on 30 December 2021. The upper deck opened on 27 May 2022 and the lower deck on 31 August 2022. The design was shaped by a height limit from nearby Wenzhou Longwan International Airport, which prevented tall towers, while low towers would obstruct the Ou River shipping channel.

The bridge carries the Yongguan Expressway on its upper deck and China National Highway 228 below, so road traffic between Yueqing and Dongtou District passes over the Oujiang estuary on two levels. Its three towers and four spans were chosen because Wenzhou Longwan International Airport limits tower height while the Ou River shipping channel needs clearance below.

The bridge carries traffic on two levels: the upper deck is a six-lane expressway (Yongguan Expressway) and the lower deck a six-lane first-class highway (China National Highway 228). Clearance under the bridge is 53.5 metres, and the deck sits 151 metres above the water. Drivers should follow signs for the correct level depending on their route.

The bridge's three-tower design was forced by Wenzhou Longwan International Airport's height limit: towers could not rise too high, yet too low a tower would obstruct the Ou River shipping channel. The result was the world's first three-tower, four-span double-decked steel truss suspension bridge, with a 2 × 800 m main span and 53.5 m clearance beneath.