Frequently asked questions - Mount Ousley interchange

The project is an interchange on the M1 Princes Motorway at the base of Mount Ousley, replacing the existing intersection which currently experiences long queues and delays during peak periods.

$300 million has been allocated jointly by the Australian and NSW Governments. The Australian Government has committed $240 million and the NSW Government has committed $60 million to build the Mount Ousley interchange.

The concept design is complete and we have carried out detailed geotechnical investigations to help inform the detailed design. Contractors have prepared tender submissions forthe detailed design and construction of the project. Once a contractor has been chosen, they will finalise the detailed design and start site establishment activities. Relocation of utility services started in early 2023 and major construction is expected to start in 2024.

Before construction can start, several important milestones must be met. These include: requesting tender by qualified contractors for the detailed design and construction of the project, finalising the detailed design, acquiring property, tender award, preparing contract documents, carrying out changes to utility locations and geotechnical investigations.

• Heavy vehicle only bypass lanes for southbound travel which will separate cars and heavy vehicles exiting at Mount Ousley.
• Two new heavy vehicle safety ramps.
• A new southbound service road between Mount Ousley Road and University Avenue, replacing the existing southbound University Avenue exit from the motorway. Road users will use the Mount Ousley Road exit.
• A new commuter car park relocated to the southern side of the motorway with additional parking spaces and traffic incident response facility.
• Upgrades to the existing pedestrian bridge over the motorway at Northfields Avenue, including bridge widening and changes to the eastern access ramp.
• New pedestrian and cyclist bridge over Mount Ousley Road connecting to the new bridge over the motorway and a new shared path connecting suburbs to the north with the University of Wollongong and the TAFE NSW Wollongong campus.
• Two new roundabouts and an overpass for improved access between Mount Ousley Road, M1 Princes Motorway and University of Wollongong.
• Improved pedestrian and cyclist connectivity on existing shared paths.
• A five metre noise wall along the northern side of the motorway and the southern side of Dumfries Avenue, between the end of the existing noise wall and Foothills Road.
• A five metre noise wall along the southern side of the motorway and northern side of Falder Place, between the mid-way point of Binda Street and the new western roundabout.
• A three and a half metre noise wall along the southern side of Mount Ousley Road, between Gowan Brae Avenue and the cul-de-sac at the western end, continuing south for about 50 metres.

• Replacement of the existing intersection of the M1 Princes Motorway and Mount Ousley Road which currently experiences long queues and delays during peak periods.
• Improved safety by separating cars and heavy vehicles travelling southbound.
• Improved travel times.
• Improved access between Wollongong CBD and University of Wollongong
• Improved access for pedestrians and cyclists, with a new pedestrian and cyclist bridge, widening of existing pedestrian bridge and improved connectivity on existing shared paths.
• Supports growing freight movements to the south coast.
• Safer access to and from the motorway to Mount Ousley Road.

The Mount Ousley interchange has been designed to allow for a third southbound lane in the future, but a third southbound lane will not be built as part of this project.

The commuter car park will be closed during construction. The new relocated car park will be opened when construction is complete. Dates for the closure will be advised before construction starts.

Construction activities will be staged to minimise impacts on road users during construction, however there will some temporary impacts to allow us to safely carry out work.

Two lanes of traffic will be kept open in both directions on the motorway during the day. A reduction in speed limit may be in place.

Night work will be carried out and will include reduced speed limits and both single lane and full closures of the motorway. Road users and nearby residents will be notified in advance.

The right turn from Mount Ousley Road onto the motorway (northbound) will be closed at certain times to allow us to carry out work. When closed, temporary detours will be in place and detours will be clearly signposted.

Along with work on the motorway, there will be work on local roads. These include utility relocation and access of construction vehicles to and from the construction site. Details of these works will be advised closer to the start date.

We understand noise can cause disruption to local communities during construction and operation of major road projects. There are generally two types of noise which may impact the community:

1. Construction noise – Temporary noise from construction activities while we build the project
2. Operational noise – Noise from road traffic once the project is complete.

Residents who live near our work sites may hear noise during construction activities, including when we are working on the road or at nearby work sites and delivering or removing material and equipment. Construction noise is temporary and often changes as work progresses.

To minimise the impact of noise, we use a range of mitigation measures to manage noise at the source. This includes temporary noise barriers around specific work areas, using less noisy equipment and staging our work to avoid extended periods of disruption.

We will be in contact with you throughout construction about how our work may impact you.

The project aims to reduce operational noise by building noise walls and installing at-property noise treatments to eligible properties.

We will be building or extending noise walls in three locations.

• A five metre noise wall along the northern side of the motorway and the southern side of Dumfries Avenue, between the end of the existing noise wall and Foothills Road.
• A five metre noise wall along the southern side of the motorway and northern side of Falder Place, between the mid-way point of Binda Street and the new western roundabout.
• A three and a half metre noise wall along the southern side of Mount Ousley Road, between Gowan Brae Avenue and the cul-de-sac at the western end, continuing south for about 40 to 50 metres to shield the properties at the western end of Mount Ousley Road.

We will carry out at-property noise treatments at homes where noise levels are predicted to exceed the road traffic noise criteria.

To minimise the impact of noise on local residents, we are delivering at-property noise treatment to eligible properties. Noise treatment refers to architectural acoustic measures which aim to improve the sound resistance of properties, such as window and door upgrades.

Providing at-property noise treatment is a complex process and involves a number of different steps. It is an extensive process as every property is different and requires a tailored package of treatments. For some properties, we also need to seek approval from Owners Corporations for certain treatments.

Yes, all southbound heavy vehicles will need to exit earlier than light vehicles onto the new heavy vehicle bypass lane. From here heavy vehicles will either travel under Mount Ousley Road to continue south on the motorway or exit onto Mount Ousley Road for access to Wollongong. This separates heavy vehicles from general southbound traffic and light vehicles exiting at Mount Ousley Road. Two new heavy vehicle safety ramps will also be provided at this location.

The heavy vehicle bypass and exit ramp will be one standard lane with a shoulder.

There may be some temporary closures and detours of shared paths while work is carried out. Detours will be put in place to safely separate shared path users and construction work areas. We will inform you of any changes in advance.

We will build a new pedestrian bridge over Mount Ousley Road, connecting Dumfries Avenue, Mount Ousley Road, University of Wollongong (south of the motorway) to the existing shared path alongside the TAFE NSW Wollongong campus.

We will also upgrade and extend the existing pedestrian bridge across the motorway to Northfields Avenue.

During construction, pedestrians will be temporarily detoured via the University Avenue overpass. Options to complete this work outside peak student periods are being investigated.