December 2025
Closure of the northbound side of the bridge
To safely complete the main construction works on Commonwealth Avenue Bridge, it is necessary to close each side of the bridge for around 12 months per side. The northbound side of the bridge will close first.
Temporary crossover lanes have been constructed to the north and south of the bridge to facilitate movement of road users onto the open side of the bridge. Prior to closing the northbound side of the bridge, traffic changes are required to install permanent bollards (separating the northbound and southbound traffic lanes), signage and line marking.
It will take approximately three days to complete these works with the full closure of the northbound side of the bridge in effect from Thursday 8 January 2026 (weather permitting).
Key information for road and shared path users
See Construction for further information on the implementation of the Stage 1 closure and diagrams of the changed traffic arrangements.
The National Capital Authority is undertaking major renewal works of Commonwealth Avenue Bridge. The project involves bridge strengthening and widening of the shared paths to cater to Canberra’s long-term transport needs while maintaining the bridge’s heritage value.
Please note these works are not connected with any light rail projects.
The Commonwealth Avenue Bridge we know today was constructed and opened to traffic in late 1963. Part of the dual carriageway Commonwealth Avenue, the bridge consists of two separate and parallel structures of around 310 metres long. It is a critical and strategically important arterial corridor in Canberra’s metropolitan transport network catering to public transport, active travel and vehicular traffic.
Learn more about the history of Commonwealth Avenue Bridge on the Attractions page.
Due to its remarkable engineering design, the Commonwealth Avenue Bridge has not undergone any significant upgrades for sixty years. However, the time for these upgrades has come. Once work is completed the bridge will be strengthened to respond to the growing population, increased traffic and new vehicles as well as to provide better access for pedestrians and cyclists across, to and from the bridge.
2021
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2023/2024
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Early 2028
Seymour Whyte was awarded the detailed design and construct contract in March 2025. As part of the detailed design phase, investigations including survey and geotechnical works were carried out between April and September 2025.
A site compound has been set up in the Barrine Drive short stay carpark. The carpark is being permanently removed as part of these works. The main site compound has been established south of Commonwealth Avenue Bridge within the Flynn Drive cloverleaf for the construction period.
Construction will be completed in two main stages with each stage anticipated to take around 12 months.
Due to the nature of the works being undertaken to strengthen the bridge, it is necessary to close each side of the bridge one at a time to enable the upgrades. This includes the traffic lanes and the shared path. One side of the bridge will remain open to accommodate traffic and shared path users. There will be one lane of general vehicle traffic in both directions. The second northbound lane will be a bus and emergency services priority lane.
To ensure all activities are completed as safely and efficiently as possible, hours of work during the construction phase will be:
Any activities requiring completion outside of these hours will be notified to the community ahead of time.
There will be significant changes and traffic impacts, including for shared path users.
Each side of Commonwealth Avenue Bridge will be closed for up to 12 months each (weather permitting). This includes the traffic lanes and the shared path. One side of the bridge will remain open.
We have been working closely with the ACT Government on traffic arrangements for the construction period. During construction there will be two northbound lanes and one southbound lane available on the open bridge side. There will be one lane of general traffic in both directions. The second northbound lane will be a bus and emergency services priority lane.
Prior to implementing the full closure of the northbound side of the bridge, traffic changes are required to install permanent bollards (separating the northbound and southbound traffic lanes), signage and line marking. It will take approximately three days to complete these works with the full closure of the northbound side of the bridge in effect from Thursday 8 January 2026 (weather permitting).
The table below outlines traffic changes from Tuesday 6 January to Thursday 8 January 2026. You can also review diagrams of these changes here.
| Timing (note: approximate) | Arrangements |
| Tuesday 6 January 2026 from 6:45am to 5:00pm | The Flynn Drive on-ramp to Commonwealth Avenue Bridge will be closed to general traffic. Access will be maintained for Transport Canberra vehicles. |
| Tuesday 6 January, 10:00am to Wednesday 7 January 2026, 3:30pm |
Southbound traffic will be reduced to one lane only and moved into the median (far right) lane. All three northbound lanes and both shared paths will remain open. |
| Wednesday 7 January, 3:30pm to Thursday 8 January, 2026 6:00am |
Southbound traffic will remain one lane only, moving into the far-left lane. Southbound traffic will remain here for the duration of Stage 1. All three northbound lanes and both shared paths will remain open. |
| Thursday 8 January 2026, from 6:00am | The Flynn Drive on-ramp to Commonwealth Avenue Bridge will close to general traffic for the duration of Stage 1. Access will be maintained for Transport Canberra vehicles. |
| Thursday 8 January 2026, 6:00am to 1:00pm |
Northbound traffic (including buses) will be reduced to one lane only on the northbound bridge and moved into the far-left lane. The shared path on the northbound side of the bridge closes for the duration of Stage 1. |
| Thursday 8 January 2026, 1:00pm to 3:00pm | All northbound traffic will move onto the southbound bridge into the middle general traffic lane via the crossover lane. The northbound bus and emergency services priority lane will remain closed. |
| Thursday 8 January 2026, 3:00pm | The northbound bus and emergency services priority lane will open. |
Canberrans and visitors to the National Capital can expect the following changes from Thursday 8 January 2025 and for the duration of Stage 1 (approximately 12 months, weather permitting):
Note: There will be no stair access for shared path users along the southbound side of the bridge. The ramps at both ends will remain open.
Download a PDF copy of the map here.
There will be significant disruptions to the road network during construction and road users are encouraged to allow extra travel time and consider what choices you can make to improve your commute. If possible, travel outside peak times, allow extra time for your trip or find other ways to travel.
There will be changes for public transport users. More information will be published by Transport Canberra on their website at www.transport.act.gov.au when available.
The road network will be monitored and we will work closely with the ACT Government to regularly communicate about impacts and alternate routes. We are committed to completing works as efficiently and safely as possible.
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If you would like to contact the project team, email us at communications@nca.gov.au
26 November 2025: Commonwealth Avenue Bridge span closure from Wednesday 7 January 2026
10 November 2025: Construction to get underway for the Commonwealth Avenue Bridge Renewal Project
21 October 2025: Essential upgrade works for Commonwealth Avenue Bridge to begin soon
26 August 2025: Commonwealth Avenue Bridge Renewal Update
7 March 2025: Commonwealth Avenue Bridge Renewal Project Update
6 October 2022: NCA to undertake major asset renewal for Commonwealth Avenue Bridge
Due to its remarkable engineering design, Commonwealth Avenue Bridge has not undergone any significant upgrades for sixty years. In this time we have seen the size and weight of everyday vehicles increase. It is important to ensure the bridge is upgraded to accommodate these increasing vehicle sizes today and into the future.
Whilst these strengthening works will increase the bridge’s load rating to accommodate heavier vehicles up to 44 tonnes, vehicle limits across the bridge will remain consistent with the authorised heavy vehicle routes determined by the National Heavy Vehicle Regulator.
In addition to the traffic lanes, Commonwealth Avenue Bridge is the primary north-south link for pedestrians and active travel users. At only 2.4 metres wide, the existing shared paths on both sides of the bridge do not meet Austroad Guidelines or industry standards. The project will double the width of the path system, significantly improving safety for both pedestrians and cyclists.
On 8 April 2022, the Minister for the Environment included Lake Burley Griffin and Adjacent Lands in the Commonwealth Heritage List. Commonwealth Avenue Bridge is not itself heritage listed, but it is included within the boundary of the Lake Burley Griffin listed area and contributes to its heritage values.
A heritage impact assessment has been prepared as part of the design for the works.
The report identified the proposed works would have a moderate impact on several heritage values because of the bridge widening which would remove parts of the original structure and handrails, impacting several creative qualities. However, the design of the extensions to the bridge has sought to minimise the impact through the simple, modern form and materials selected.
There was also a minor impact noted because of the bridge’s changed appearance, including to the landscaping. These impacts would be greater at close range, but less perceptible from further away. New plantings are expected to mitigate this landscape impact over time.
Otherwise, no additional heritage values were noted.
The project will have regard for preserving the historical significance of the bridge.
The upgraded bridge will generally retain its current visual appearance. New materials being used to upgrade the bridge will not be visible due to their location within the bridge and those used for the widening of the bridge will complement the existing look of the bridge.
Both sets of flagpoles have been removed to allow construction activities associated with the project to take place. There are no current plans to reinstate the flagpoles following construction. The flagpoles along Kings Avenue will remain.
The project includes increasing the width of the shared pathways on either side of the bridges to roughly 5m wide. In addition, pedestrian paths on the northern and southern abutments of the bridge will be realigned to allow safer movement of pedestrians and cyclist when exiting the bridge.
There will be significant closures and traffic impacts during construction and Canberrans are urged to plan ahead and, if possible, consider changes to how you travel.
To ensure one side of the bridge remains open, works will be undertaken on the northbound side of the bridge first, before progressing to the southbound side.
During construction there will be two northbound lanes and one southbound lane available on the open bridge side. There will be one lane of general vehicle traffic in both directions. The second northbound lane will be a bus and emergency services priority lane.
The road network will be monitored and we will work closely with the ACT Government to communicate about impacts and alternate routes. We recognise this is going to be disruptive for the community and visitors to the National Capital and are committed to completing works as efficiently and safely as possible.
The water level of Lake Burley Griffin is lowered to manage risks associated with construction activities on the Scrivener Dam Dissipator Strengthening Project. The lake is lowered to a maximum of 500mm below normal levels for the duration of construction.
On the Commonwealth Avenue Bridge Renewal Project, the majority of works will occur either inside the bridge deck or beneath the bridge and may not be highly visible to the public. Works beneath the bridge will be carried out from barges and these will begin to arrive in January 2026. There will be some impacts for lake users, including gradual closures of sections of the lake beneath the bridge as works progress. Maps will be provided on this page and to the Lake User Group when available.
We urge all lake users to consider the impacts and potential new hazards prior to setting out onto the water.
The NCA has and will continue to work closely with the ACT Government to minimise impacts for all road users as much as possible during the construction period. A dedicated northbound bus priority lane will be provided. Further information about public transport arrangements during the construction period will be published at www.transport.act.gov.au when available.
Due to the nature of the works being undertaken to strengthen the bridge, it is necessary to close the bridge. These works include replacement of the bridge bearings which sit between the bridge deck and the bridge piers. The bridge will be lifted off the existing piers to complete this work and it is critical there is no additional load on the bridge during this time.
Furthermore, as part of the works holes will be cut in the bridge deck to allow access for pouring the reinforced concrete slabs inside the bridge. Both these activities necessitate the closure of the affected bridge side to ensure the safety of both the workers and the public.
Both the NCA and our contractors are subject to the highest standards of work, health and safety and these guide us in developing our construction programs. It is important to acknowledge we are working in a very constrained environment both in terms of confined spaces within the bridge and the added challenge of working over water.
The NCA considered the options of extended hours of work, however this would significantly increase cost of the project and increase on-site risks during construction. All these factors were considered and balanced appropriately. We are committed to completing works as efficiently and safely as possible and will seek to identify opportunities to accelerate works where possible.
The Commonwealth Avenue Bridge Renewal Project is unrelated to the ACT Government's plan to extend the Light Rail from Civic to Woden.
To learn more about the light rail project, please visit the ACT Government's website.
The NCA is working closely with the ACT Government to coordinate construction programs, disruption and communication activities wherever possible.
The area of Commonwealth Avenue Bridge is a constrained environment. To complete these necessary upgrades, our project team needs to work above, below and between the two bridge spans. To construct these works at the same time as the proposed works being delivered with Light Rail Stage 2B would further constrain the environment, making it unsafe for two project teams and all the necessary machinery and activities to co-exist.
The NCA will continue to work with stakeholders, including the ACT Government, to manage the impact of this project and its interrelationship with other works in and around the vicinity.
The NCA will continue to keep community members and other stakeholders updated on project status and arrangements for traffic management once construction works commence.
You can stay informed by subscribing to our mailing list using the link above, or by following the project updates on our website or social media. If you have any questions about the project you can email us at communications@nca.gov.au
We acknowledge the Ngunnawal people as traditional custodians of the ACT and recognise any other people or families with connection to the lands of the ACT and region.
We acknowledge and respect their continuing culture and the contribution they make to the life of this city and this region.