The proposed 3.5 km long Millennium Gateway Bridge will cross the Strait of Penang as part of a Master Plan Project to develop Penang and the northern region of Malaysia. The bridge will provide a vital transportation link to integrate Penang Island, the new CITI 21 Island and the Malaysia mainland. The bridge will likely become an important landmark in this region.

OPAC was engaged by T.Y. Lin South East Asia of Singapore as part of a team to perform a conceptual study for the bridge. The purposes of the study were to develop and recommend conceptual bridge layouts, including approximate locations of main piers and type and lengths of main spans, and develop an estimated construction cost for each bridge layout.

The water depth, ship traffic, and desire for a landmark bridge led to in-depth study of three cable-supported bridge types, each with 2 main spans of 700 m:

• Suspension bridge with 280 m side spans.
• Cable-stayed bridge with 350 m side spans.
• Hybrid stayed-suspension bridge with 300 m side spans.

Several foundation types were studied, including piles, drilled shafts, and sunken caissons. The hybrid stayed-suspension bridge was favorably received due to its relative economy, unusual appearance, and structural rigidity.