The road and rail bridges will be high-level opening bridges to retain the functionality of the Inner Harbour as an active waterway. The basic design of the bridges incorporates the following features:

• a four-lane road bridge approximately 300 metres in length with eight fixed spans
• a shared path for pedestrians and cyclists
• a single track, dual gauge rail bridge approximately one kilometre in length with 23 fixed spans
• ten metres clearance to Mean Sea Level (approximately eight metres above high water) to allow tourist boats and smaller vessels unlimited passage
• 180 river based piles will be used for the road and rail bridges, each of which are 30 metres long and 900 millimetres in diameter
• 460 land based piles will be used for the road and rail bridges
• opening spans to provide a 30 metre opening to allow tall ships and larger vessels passage
• a clear zone of 11 metres wide from the eastern wharf edge and eight metres from the western wharf edge as well as a minimum of 4.6 metres in height under the bridge to allow for public boardwalks around the waterfront which will be developed as part of the Port Adelaide Waterfront Redevelopment project
• an "open" feeling through the spacing and dimensions of the piers providing access under and around the bridges to minimise the impact on the surrounding environment
• a large window (glass curtain wall) to facilitate viewing of the bridges' opening mechanisms
• viewing platforms on the road bridge, with stairs and ramps providing access from wharf level
• inclusion of back up mechanisms to ensure the reliability of opening and closing bridges in the event of a power failure. These include emergency power sources and manual opening mechanisms
• fendering of the navigation channel between the two bridges to provide protection of the bridge bascule and rest piers
• landscaping and urban design initiatives that are consistent with the character of Port Adelaide and the Port Waterfront Redevelopment project will be included in Stages 2 and 3
• the road bridge of the Port River Expressway will be known as the 'Power Bridge'. The rail bridge will be named the 'Mary MacKillop Bridge' in honour of Mary Mackillop, who played an important role in the state's history and was beatified by Pope John Paul II in 1995.
• the opening span of the road bridge is 58 metres long and weighs approximately 2000 tonnes
• the rail bridge opening span weighs 1200 tonnes and is 62 metres long