Major overnight closures are planned for the busy M1 Princes Motorway as a critical phase of the Mount Ousley interchange project gets underway.
Bridge Construction to Disrupt Key Freight Route
Transport for NSW has confirmed that building the two new bridges for the $390 million interchange upgrade will necessitate full closures of the motorway at night. The project, which began nearly two years ago, is scheduled for completion in 2028.
The massive upgrade aims to create a safer route for northbound traffic and establish a new entrance to the University of Wollongong. Construction on bridge abutments and foundations started early this year, and the piers and retaining walls are now visible from the road.
Timing and Details of Planned Night Closures
A spokesperson for Transport for NSW stated that the installation of the bridge girders is not expected to happen immediately but will occur in the future. When it does, it will mirror previous full night closures conducted as part of the project, the most recent of which was in June 2025.
"Full closures at night will be required to safely install the girders for the bridges over the M1 Princes Motorway," the spokesperson said. "These will be implemented similar to the full night closures that have already occurred."
The closures are typically carried out in blocks of six over a two-week period, between the hours of 8pm and 4am. The affected section is the motorway from Bulli Pass to Memorial Drive.
Detour Routes and Impact on Heavy Vehicles
During the closures, the main detour for light vehicles and heavy vehicles under 19 metres and 50.5 tonnes will be via Bulli Pass. However, this route is not suitable for larger freight.
Vehicles exceeding those dimensions are advised to delay their journeys or will be parked, as no alternative route can accommodate them. Other road users travelling between Wollongong and the Hume Motorway can detour via Memorial Drive, Bulli Pass, Appin Road, or Macquarie Pass.
Transport for NSW has acknowledged the significant impact of these closures on the community, freight operators, and motorists. The agency pledges to continue engagement with all stakeholders ahead of any planned works. Local access to Mount Ousley Road between the Princes Highway and Gowan Brae Avenue will be maintained throughout the closures.
The new interchange will eventually feature two bridges crossing over the motorway: one for a heavy vehicle bypass lane and a second linking to the new northern entrance of the University of Wollongong.
