Frequently asked questions

This information has been developed to provide more detail about the preferred option and proposed upgrades to the intersection, and to provide answers to frequently asked questions from stakeholders and the community.

The Frequently asked Questions are also available to view or download as a PDF on the media page of the portal.

Currently, motorists are experiencing significant delays, long queues and wait times at the intersection, particularly during AM, PM, and weekend peak periods, and during special events at Sydney Olympic Park.

Congestion at the intersection impacts the local network, connectivity to Sydney Olympic Park and Homebush for all road users, bus service reliability for 525 and 526 bus routes, as well as reliable and efficient movement of commuters and freight movements within the regional traffic network.

Pre COVID-19 (December 2018) traffic counts indicate that around 4,500 vehicles per hour travel through the intersection during the weekday AM and PM peak periods. The intersection will see increasing traffic use in the years to come as Sydney Olympic Park and surrounds continue to develop.

The existing intersection also performs poorly in terms of road safety with 44 crashes reported at the intersection between 2016 and 2020. Contributing factors to this poor crash history could include congested traffic conditions, poor gap acceptance for vehicles entering the roundabout, poor legibility and signage, and poor lighting underneath the existing Homebush Bay Drive overbridge. Of the crashes, almost half were associated with rear-end crashes, reflecting the congested conditions during peak hours.

The proposed upgrade will ease congestion, increase safety, and improve travel times to Homebush and Sydney Olympic Park.

The Australian and NSW Governments are jointly funding the $100 million proposed Homebush Bay Drive and Australia Avenue upgrade. Transport for NSW is responsible for developing and building the upgrade improvements.

Key features of the preferred option include:

  • upgrading the existing roundabout to a signalised intersection to allow for real-time peak period adjustments
  • widening Australia Avenue, Underwood Road and Homebush Bay Drive
  • (southbound) off ramp approaches to three lanes
  • providing a U turn lane on the Homebush Bay Drive (northbound) approach to allow traffic flow back onto Homebush Bay Drive (southbound) on ramp, towards M4 Motorway
  • providing left slip lanes at all approaches
  • widening existing pedestrian footpaths on Australia Avenue and Underwood Road to provide shared use (pedestrian and cyclist) pathways
  • providing coordinated pedestrian activated traffic signals on all approaches
  • building a signalised shared use crossing on Australia Avenue
  • upgrading existing signalised pedestrian crossings on Homebush Bay Drive on and off ramp approaches and Underwood Road to signalised shared use crossings
  • building new shared use refuge islands

Proposed changes at Homebush Bay Drive (northbound) off ramp include:

  • modifying the existing two lanes to provide dual right lanes towards Underwood Road
  • providing a U turn lane ahead of the approach to allow traffic flow back onto Homebush Bay Drive (southbound) on ramp, towards M4 Motorway
  • improving the existing left slip lane onto Australia Avenue, towards Sydney Olympic Park
  • upgrading the existing signalised pedestrian crossing to a shared use (pedestrian and cyclist) crossing, with pedestrian activated traffic signals
  • building shared use refuge islands to improve connectivity to Bicentennial Park and Direct Factory Outlet (DFO) Homebush

Proposed changes at Homebush Bay Drive (southbound) off ramp include:

  • widening the approach from two to three lanes, to provide one through lane onto Homebush Bay Drive (southbound) on ramp, towards M4 Motorway, and two right lanes, towards Australia Avenue
  • providing a left slip lane onto Underwood Road
  • upgrading the existing signalised pedestrian crossing to a shared use (pedestrian and cyclist) crossing, with pedestrian activated traffic signals
  • building shared use refuge islands to improve connectivity to Bicentennial Park

Proposed changes at Australia Avenue include:

  • widening the approach from two to three lanes to provide one through lane towards Underwood Road, one through/right lane towards Underwood Road/Homebush Bay Drive (southbound) on ramp and one right lane towards Homebush Bay Drive (southbound) on ramp, towards M4 Motorway
  • improving the existing left slip lane onto Homebush Bay Drive (northbound) on ramp, towards Concord
  • widening the existing pedestrian footpath to provide a shared use (pedestrian and cyclist) pathway
  • building a shared use crossing on Australia Avenue with pedestrian activated traffic signals
  • building shared use refuge islands to improve connectivity to Sydney Olympic Park and Bicentennial Park
  • improving existing on-road bicycle lanes on Australia Avenue.

Proposed changes at Underwood Road include:

  • widening the approach from two to three lanes, to provide two through lanes towards Australia Avenue and one right lane towards Homebush Bay Drive(northbound) on ramp, towards Concord
  • providing a left slip lane onto Homebush Bay Drive (southbound) on ramp, towards M4 Motorway
  • widening existing pedestrian footpath to provide a shared use (pedestrian and cyclist) pathway
  • upgrading the existing signalised pedestrian crossing to a shared use crossing, with pedestrian activated traffic signals
  • building a new shared use refuge island to improve connectivity to Bressington Park and Direct Factory Outlet (DFO) Homebush

Key benefits include:

  • improved connectivity to Sydney Olympic Park residential, recreational and commercial growth areas
  • improved traffic flow and performance at the intersection
  • improved travel time savings for all road users, particularly during AM, PM and weekend peaks, and during special events at Sydney Olympic Park
  • improved travel times and service reliability for 525 and 526 bus routes users
  • improved safety for all road users at the intersection and approaches
  • safer and more efficient travel for pedestrians and cyclists
  • reduced vehicle operating costs for all road users
  • improved environmental and visual amenity

The preferred option was selected following a thorough planning, investigation and development process. This included three value management workshops held in 2021. Key stakeholders from Transport for NSW, City of Parramatta Council, Strathfield Municipal Council, NSW Department of Planning and Environment, Sydney Olympic Park Authority and the Federal Department of Infrastructure, Transport, Regional Development and Communications were all invited to attend the workshops.

Initially 12 options were identified for assessment for the project. Options identified and considered included roundabout improvements, overpasses, underpasses, and various signalised intersection options. A comparative assessment was carried out to assess the impacts and constraints of the 12 options, using a number of technical studies and investigations.

These options were comparatively assessed against:

  • road safety
  • traffic efficiency and capacity
  • pedestrian and cyclist connectivity
  • environmental impacts
  • property and community needs
  • construction and design benefits
  • delivery cost and budget

A signalised intersection, configured as a Diverging Diamond Interchange performed best overall when compared with the other options, and was selected as the preferred option. This innovative intersection arrangement will improve safety, efficiency, and capacity at the intersection more effectively than a conventional signalised intersection. The Preferred Option Report provides more detail on the option selection process. This report is now available to read or download from the Media section of the portal.

A Diverging Diamond Interchange is an innovative signalised intersection which will provide a new way of managing existing traffic volumes and increasing demands at the intersection of Homebush Bay Drive, Australia Avenue and Underwood Road. This new configuration will improve safety for all road users and keep large traffic volumes moving quickly and efficiently.

There are currently 135 Diverging Diamond Interchanges throughout nine countries worldwide, the most being in the USA (123). In Australia there is a Diverging Diamond Interchange in operation at Caloundra Road and Bruce Highway Queensland. Two further Diverging Diamond Interchanges are in construction in Queensland, at Gympie Arterial Road and Strathpine Road and the Bruce Highway and the Pacific Motorway (M1) Varsity Lakes to Burleigh.

While new to NSW drivers, the Homebush Bay Drive and Australia Avenue Diverging Diamond Interchange will be both easy and safe to navigate.

While this type of signalised intersection is new to NSW drivers, the intersection will be easy and safe to navigate. The design is unique, in that it requires traffic to briefly drive on the opposite side of the road, from what is customary, as traffic safely moves through the intersection. The crossover of traffic will be undertaken under the safety of signalised intersections, which will increase traffic efficiency and remove conflicts with opposing vehicles.

The design allows traffic movements to be controlled by traffic signals with simplified traffic signal phasing, providing increased green time within the intersection. The layout also provides a significant improvement in safety, since right turn movements no longer need to wait for opposing through traffic to clear to find a safe gap.

The design will also improve the efficiency of the intersection, as the lost time for various phases in the cycle can be redistributed as green time. By grouping traffic approaches together through the intersection there will be a significant reduction of signal phases when compared with conventional intersection layouts which consist of six or more phases.

The preferred option was found to improve safety, efficiency, and capacity at the intersection more effectively than a conventional signalised intersection. The existing Homebush Bay Drive bridge structure, including the location of the bridge piers, would also prevent a conventional signalised intersection being provided without extensive modifications to the existing bridge structure. This in turn would result in a longer construction time, with potential major construction traffic impacts, compared to the preferred option.

The key benefits of the proposed Diverging Diamond Interchange over a conventional signalised intersection include:

  • reduced intersection conflict points
  • improved intersection efficiency
  • minimised traffic disruption during construction
  • minimised construction build time
  • better value for money

Proposed widening of Australia Avenue and Underwood Road will have land impacts to the corners of Bicentennial and Bressington Parks next to the intersection. Transport for NSW will consult with City of Parramatta Council, Strathfield Municipal Council and Sydney Olympic Park Authority and minimise impacts wherever possible as planning progresses.

The preferred option supports better connectivity for the large number of active transport and bus users accessing the area for shopping, commercial and recreational purposes.

Walking, cycling and public transport will be supported by:

  • providing more efficient and reliable services for 525 and 526 bus route users
  • widening existing pedestrian footpaths on Australia Avenue and Underwood Road to provide shared use (pedestrian and cyclist) pathways
  • providing coordinated pedestrian activated traffic signals on all approaches to minimise waiting time
  • building a new shared use path crossing on Australia Avenue with pedestrian activated traffic signals
  • upgrading existing signalised pedestrian crossings on Homebush Bay Drive on/off ramp approaches and Underwood Road to shared use crossings with pedestrian activate traffic signals
  • building new shared use refuge islands
  • improving existing on-road bicycle lanes on Australia Avenue

Subject to planning approval, construction is expected to commence in 2025, and take about 18 months to complete.

The area is supported by other NSW Government transport projects which will significantly improve connectivity between Sydney Olympic Park, Parramatta and Sydney CBDs into the future. These include:

Connectivity to Sydney Olympic Park will be improved, and travel times to and from Sydney and Parramatta CBDs reduced, by Sydney Metro and proposed Parramatta Light Rail Stage 2 connections to Sydney Olympic Park.

Community feedback has been extended from Sunday 29 May 2022 at 5PM to Sunday 5 June 2022 at 5PM.

Once the consultation period closes Transport for NSW will carefully consider all feedback received. A report which summarises feedback, and our responses, will be published later this year on the project webpage.

We will continue to keep community members and stakeholders informed as planning progresses by community notifications and updates to the project webpage.

If you would like to receive project updates direct to your email, please email australia.avenue@transport.nsw.gov.au and we will add you to our mailing list.

Once the consultation period closes Transport for NSW will carefully consider all feedback received. A report which summarises feedback, and our responses, will be published on the project webpage.

We will continue to keep community members and stakeholders informed as planning progresses by community notifications and updates to the project webpage.

During the session our project team will explain the proposed upgrade and answer any questions you may have. This session can be joined using the following link nswroads.work/ausaveinfosession.

We encourage you to submit your questions in advance by emailing or calling the team.

Feedback can be made by:

  • Calling our project team on 1800 844 199 (during business hours)
  • Emailing our project team at australia.avenue@transport.nsw.gov.au
  • Leaving a comment on our interactive map
  • Writing to our project team at Homebush Bay Drive and Australia Avenue intersection upgrade Central River City Level 11, 130 George Street, PARRAMATTA NSW 2150

For further information contact the project team at australia.avenue@transport.nsw.gov.au or 1800 844 199 (during business hours).