The upgrade is driven by the Western Harbour Tunnel project, a $7.4 billion link designed to bypass the CBD and connect the WestConnex motorway to the Warringah Freeway, with a planned late-2028 opening.

Completion is targeted for November next year, though delays of six to nine months have occurred; a major disruption period is planned during the summer holidays for critical works.

A southbound bus lane from Cammeray is largely complete and will be bus-only in the second quarter of next year to boost public transport efficiency.

Officials say the project will streamline Sydney’s biggest traffic bottleneck by reconfiguring lanes and improving connections, while balancing disruption and resident impact.

Main tunnel exits/entries will be at Cammeray, with a southbound entry from Berry Street to the under-harbour crossing, and a near-180-degree arc to assist North Sydney-to-southbound navigation.

Traffic management includes channelisation to reduce lane changes, fewer mergers, and new lane configurations, with night work limited to about 10 nights per month due to noise restrictions and daytime work preferred.

The Warringah Freeway upgrade, a $2.08 billion project, is described as the toughest road-building job given its complexity and traffic volume—up to 220,000 vehicles daily.

Officials emphasize progressive openings rather than a single ceremony, noting ongoing changes such as reduced lane-for-merger flexibility as elements near completion in 2026.

Transport for NSW notes the project’s difficulty, likening it to a three-dimensional Tetris challenge with frequent lane closures and more than 20,000 changes.

Recent works include a 46-metre underpass linking directly to Cahill Expressway, a 187-metre pedestrian and cyclist bridge over the freeway, a new shared-user bridge connecting Ridge Street to Alfred Street North, and a widened High Street bridge.