WestConnex

WestConnex is a 33-kilometre (21 mi) predominantly underground motorway scheme in Sydney, New South Wales, Australia. A joint project of the New South Wales and Federal governments, the motorway scheme created around 26 kilometres (16 mi) of new tunnels between Homebush and Kingsgrove, passing underneath Inner West suburbs including Haberfield and St Peters. The first of the tunnels, the M4 East, opened to traffic in July 2019. The second of the tunnels, the M8 Motorway, opened to traffic a year later in July 2020. The third of the tunnels which extend the M4 and M8 opened to traffic in January 2023. The final component of the scheme, the Rozelle Interchange, opened to traffic in November 2023.

The forecast cost of WestConnex has grown from A$10 billion to over $16.8 billion. Once land acquisitions, network extensions development costs and the cost of operations are accounted for, the total cost is forecast to be at least $20 billion and possibly as much as $45 billion. In August 2018, the NSW government sold 51 percent of WestConnex to a consortium led by Transurban for A$9.26 billion.

The project has bipartisan political support from the coalition and Labor parties, at both a federal and state level. Described as "the biggest transport project in Sydney and Australia since the Harbour Bridge" and costing "in current dollars, double the Snowy Mountains Scheme", the project has been criticised on economic, social and process grounds and has been the subject of public protest. It has faced opposition from residents, pro-public transport groups, anti-toll groups, and councillors from impacted suburbs, including the Lord Mayor of Sydney Clover Moore, and the Greens. In June 2017, the City of Sydney called on the government to abandon the third and final stage of the project.