WestConnex Rozelle Interchange

McGregor Coxall were engaged by Infrastructure NSW to investigate the Rozelle Interchange, a critical node within the $16.8 billion WestConnex program, jointly funded by the Australian Government and the NSW Government.

The interchange was originally conceived as an extensive above-ground cloverleaf network of elevated roads, sited on the former Rozelle Railyards, a large, flat parcel of land previously used as a coal railhead servicing the White Bay Power Station. While the engineering logic was clear, the proposal would have severely reinforced the historical disconnection between communities on either side of the site, entrenching a barrier that the redundant rail yard had already created for decades.

McGregor Coxall was initially engaged to provide an urban planting overlay to ameliorate the visual impact of the elevated road network. Following analysis we identified a far greater opportunity: solve urban disconnection by adding a large scale elevated green roof over the cloverleaf to unite the suburbs on either side of the motorway. This transformed grey infrastructure to green.

Recognising that tunnel boring machines were already operational for the broader WestConnex tunnels and surfacing at this very location, we proposed a bold alternative, to continue the underground tunnel network and resolve the full interchange complexity below ground. This would liberate the entire surface for continuous public parklands, reconnecting the communities that the former railyard had long divided.

The proposal was met with initial resistance from the engineering team, who had invested years in the above-ground solution. Through persistent advocacy, including direct engagement with Infrastructure NSW leadership and a pivotal working session with a key engineering champion who confirmed the underground approach could in fact be more economical, the concept gained traction. With strong community opposition to the elevated interchange already mounting, the parklands solution offered government a compelling alternative: better outcomes for communities, ecological regeneration, comparable or lower cost, and a powerful public narrative. The decision was made to adopt the underground interchange concept.

Project construction was undertaken by John Holland and McGregor Coxall were appointed to the NSW Government Design Review Panel to provide design guardianship.

OUTCOME

The Rozelle Parklands, nearly 10 hectares of new public open space built above the underground interchange, stand as a direct outcome of this strategic design intervention. The parklands are delivered on the site of the former Rozelle Railyards and contain over 3,000 trees, 170,000 plants, new wetlands and 14 kilometres of active transport connections linking communities from Drummoyne, Chiswick and Russell Lea through to the Anzac Bridge and Sydney CBD.

The interchange itself was delivered by a workforce of 20,000 people, who moved 6.5 million tonnes of earth and completed 16.6 kilometres of tunnels, enabling traffic-light-free access from Sydney’s west and south-west to the CBD and Inner West, described as a game-changer for motorists across the city.

The Rozelle Parklands demonstrate the transformative role that landscape architects and masterplanners can play in major infrastructure, not merely as embellishment, but as the originating force behind a city-changing idea.