General
What is the Mount Ousley interchange project?
The interchange will replace the existing intersection of the Princes Motorway and Mount Ousley Road, improving connectivity, safety and efficiency to those travelling through the gateway to Wollongong.
What is the cost of the project?
The Australian and NSW governments have jointly funded the $390 million project.
How long will the project take to complete?
The project will take up to four years to complete, weather permitting.
When will work start?
Major work is planned to start in late 2024.
Where is the project up to?
Fulton Hogan has been awarded the contract to design and build the new interchange. Early work activities and detailed design is underway.
Project information
What are the core project objectives?
The core objectives of the project include:
- Improving safety by addressing conflicting movements and the interaction between light and heavy vehicles
- Improving travel time and efficiency for vehicles travelling on this length of the M1 Princes Motorway
- Providing for the growing freight task including supporting the expanding port at Port Kembla
- Enhancing accessibility to and from the M1 Princes Motorway and the Wollongong CBD.
What are the key features?
Key features of the project include:
- A heavy vehicle bypass lane for southbound travel, separating light and heavy vehicles
- Separate off ramps for southbound light and heavy vehicles exiting the M1 Princes Motorway
- Two heavy vehicle safety ramps
- A bridge over the M1 Princes Motorway with signalised intersections connecting the M1 Princes Motorway, Mount Ousley Road and the new access road to the University of Wollongong
- A commuter car park
- A roundabout that provides access to the M1 Princes Motorway and the University access road
- A shared path along the bridge over the M1 Princes Motorway and the University access road
- A southbound access road between Mount Ousley Road and University Avenue
- A pedestrian and cyclist bridge over the southbound access road
- A shared path connecting to the existing path from Helen Street, and upgrades to the shared path adjacent to TAFE NSW Wollongong
- Upgrade and extension of the existing pedestrian bridge over the M1 Princes Motorway at Northfields Avenue
- Five metre high noise walls along the northern side of the motorway and the southern side of Dumfries Avenue; and along the southern side of the motorway and northern side of Falder Place
- Three and a half metre high noise walls along the southern side of Mount Ousley Road, between Gowan Brae Avenue and the cul-de-sac at the western end.
What are the project benefits?
Benefits of the project include:
- Improved safety by separating cars and heavy vehicles travelling southbound
- Improved travel times by replacing the existing intersection of the M1 Princes Motorway and Mount Ousley Road which currently experiences long queues and delays during peak periods
- Improved access between Wollongong CBD and University of Wollongong
- Improved amenity for pedestrians and cyclists
- Supporting growing freight movements to the south coast
- Safer access to and from the Princes Motorway to Mount Ousley Road.
Why were there changes to the scope and design?
During 2023, all aspects of the Mount Ousley interchange project were assessed to find opportunities to refine the scope and reduce overall cost while still achieving the project core objectives to improve road safety, travel times, and accommodate the efficient movement of future traffic and freight growth.
Will a third southbound lane be built for road users travelling on the M1 Princes Motorway down Mount Ousley?
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.
Heavy vehicles
How does the new heavy vehicle bypass work?
The project separates southbound heavy vehicles from other southbound traffic exiting at Mount Ousley Road. All southbound heavy vehicles will need to exit earlier onto the new heavy vehicle bypass lane.
From the heavy vehicle bypass lane, heavy vehicles will either travel under a new bridge to continue southbound or exit eastbound onto Mount Ousley Road adhering to traffic lights.
Heavy vehicles that are over 4.6 metres high will need to exit onto Mount Ousley Road and follow the approved oversize overmass (OSOM) vehicle route.
How many lanes will the heavy vehicle bypass have?
The heavy vehicle bypass and exit ramp will be one standard lane with a shoulder.
How many safety ramps will there be?
Two heavy vehicle safety ramps will be built.
Pedestrian and cyclist access
How is pedestrian and cycle connectivity being provided?
Improvements to pedestrian and cyclist connectivity as part of the project include:
- A shared path along the bridge over the motorway and the University access road
- A pedestrian and cyclist bridge over the southbound access road
- A shared path connecting to the existing path from Helen Street, and upgrades to the shared path adjacent to TAFE NSW Wollongong
- An upgrade and extension of the existing pedestrian bridge across the motorway to Northfields Avenue.
Pedestrian and cycle connectivity along Mount Ousley Road (local) will be refined as part of detailed design.
Why was the pedestrian bridge removed?
The pedestrian bridge over Mount Ousley Road was removed from the scope as part of the design refinement process for several reasons, including:
- The removal of the bridge does not impact on the achievement of the core project objectives
- The pedestrian and cycle bridge across Mount Ousley Road is not identified as a key part of the future active transport network in the area
- The demand for over-height vehicles will continue to increase in the coming years, and the proposed bridge had an impact on the over-height freight vehicle access from Port Kembla
- The existing at-grade crossing can be enhanced and used to cater for a similar connection.
How will pedestrians cross the motorway while the existing pedestrian bridge is being extended?
During this work, a temporary closure of the pedestrian bridge will be required. A detour will be in place via University Avenue overpass. The project is investigating opportunities to minimise the impact of this closure.
What are the likely impacts to pedestrians and cyclists during construction?
During construction, there will be some intermittent and short-term closures while work is carried out near the existing path adjacent to TAFE NSW Wollongong. During this work, detours will be in place to safely separate shared path users and the work area.
General construction impacts
How will the community be impacted during construction?
Construction activities will be staged to minimise impacts on road users during construction, however there will be some temporary impacts to allow us to safely carry out work.
Generally, work will take place during the day, Monday to Friday between 7am and 6pm, and Saturday between 8am and 1pm, weather permitting.
When working near live traffic, we will sometimes need to work at night to maintain safety and traffic flow. This will include lane closures and full carriageway closures of the M1 Princes Motorway and Mount Ousley Road.
If night work and traffic changes are required, nearby residents and road users will be notified in advance.
We understand that delivering infrastructure projects does not occur without impacts and we will be working closely with nearby residents, businesses and road users to keep you informed during construction.
What will the impacts be on the road network?
Two lanes of traffic will be kept open in both directions on the motorway during the day. A shoulder, lane closures and reduced speed limits will be in place.
When working near live traffic, we will sometimes need to work at night to maintain safety and traffic flow. This will include lane closures and full carriageway closures of the M1 Princes Motorway and Mount Ousley Road.
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 also be work on nearby local roads. This work will include utility relocation and movement of construction vehicles to and from the construction site.
We will be working closely with nearby residents, businesses and road users to keep you informed during construction.
Can I access the commuter carpark during construction?
Partial and full closures of the commuter car park will be required during construction. Car park users will be notified ahead of any partial or full closures.
How much vegetation is being removed?
The project’s Review of Environmental Factors (REF) assessed the potential removal of about 7.58 hectares of two (non-threatened) plant community types, about 5.05 hectares of roadside and urban plantings, and about one hectare of weed dominated vegetation.
This was further refined as part of the project’s Addendum Review of Environmental Factors (AREF) to 7.53 hectares of two (non-threatened) plant community types, about 5.38 hectares of roadside and urban plantings, and about one hectare of weed dominated vegetation.
Vegetation removal during construction may include 19 hollow bearing trees, including dead trees. During construction, every effort will be made to retain vegetation where possible.
What mitigation measures and offset will occur?
The process for vegetation removal on the project includes:
- Pre-clearing checklists and inspections including looking for ways to avoid or reduce tree impact
- Engaging with suitably qualified ecologists and vegetation removal contractors to carry out the work
- Installing nest boxes as supplementary fauna habit
- Establishing exclusion zones prior to work starting
- Implementing staged removal for identified hollow bearing and habitat trees
- Installing erosion and sediment controls.
In addition to biodiversity offsets being delivered by the project, native vegetation unique to the lower Illawarra escarpment and coastal plain will be planted following construction.
Noise
What are the noise impacts?
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:
- Construction noise – Temporary noise from construction activities while we build the project
- Operational noise – Noise from road traffic once the project is complete.
How will construction noise be managed?
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 also monitor noise during our work so we can manage impacts and adjust our work, where possible. We will continue to work with nearby residents to minimise impacts during construction.
How will operational noise be managed?
The project aims to reduce operational noise through road design and by, building noise walls and carrying out 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.
Where can I find out more about operational noise?
Visit the project website for more information about operational noise.