Described as an engineering masterpiece, “the Ferrari of bridges”, Commonwealth Avenue Bridge turns 60 this year – and the National Capital Authority has received $137 million from the federal government to strengthen and widen the bridge, extending its life for another six decades.

“The bridge has done a great job for 60 years,” NCA CEO Sally Barnes said.

“It’s in good nick, but we know that with more people, heavier vehicles, and people wanting to access it all year round, we need to do some work to strengthen it and improve the accessibility.”

The NCA will hold pop-up information sessions for the public each morning for the next four days.

• Commonwealth Avenue Bridge to receive a facelift (12 October 2022)
• Commonwealth Avenue Bridge a priority for the Federal Government (26 February 2021)

Commonwealth Avenue Bridge opened in November 1963 (the same month Aboriginal Australians first voted in federal elections, John F. Kennedy was shot, C. S. Lewis and Aldous Huxley died, and Doctor Who began).

The elegant, slimline bridge met the standards of the day, but the designers of the 1950s did not anticipate that Canberra would grow to nearly 500,000 people, or that cyclists, scooters, and pedestrians would use the bridge, Ms Barnes said.

“The bridge does not have the capacity to cater for the weight of modern vehicles or expected future traffic growth,” the NCA states. “Without intervention, its integrity might be compromised.”

Almost 1,000 pedestrians and 2,000 cyclists use the bridge during peak periods. While the cars of the 1960s were light (around 800 kg), modern vehicles like SUVs and Teslas weigh up to 3,000 kg, and are getting heavier. Traffic will increase as Canberra grows, project director Greg Tallentine said.

The NCA intends to strengthen the bridge to bring it up to the current design load standard: a 44-tonne truck load (T44) or a 44-tonne lane load (L44). The bridge was built for a 32-tonne load (the British standard of the day).

The area around the piers will be strengthened by 54 per cent, and between the piers by 12 per cent.

The bridge will be widened for pedestrian and shared access. The cycle and pedestrian pathway will be increased from 2 metres wide (enough for two people and a bicycle) to 5 metres, effectively doubling the capacity.

To do so, the outside of each bridge will be widened, which the NCA states will maintain the overall symmetry of the bridge.

The modernisation will match the bridge profile, Mr Tallentine said; it will be more complementary than radical.

The NCA will replace safety barriers and handrails, and install new lighting.

It will also landscape the surrounding area to improve urban design and access to the bridge and the lake’s foreshore. All four pedestrian approaches from lakeside to the bridge level will be enhanced, the NCA states, providing improved amenity and accessible connections along the Lake Loop.

The proposed design is based on consultation with the ACT Government and cycling advocacy group Pedal Power, Ms Barnes said.

Each morning, from Thursday to Sunday this week, Canberrans will be able to ask project managers questions, while the NCA gets feedback from lake path users about the proposed design concept.

“I’m sure when we talk to people, they will ask us what will it mean for their access to the bridge, what will it mean for their access to the Lake, what will it mean for their trips into the city,” Ms Barnes said. “We’re keen to talk to them about how best we might be able to do that.”

The public can also informally submit their comments on the designs directly to the project team via the website.

The NCA will formally submit the project to the Parliamentary Standing Committee on Public Works in May, then go to out to market for someone to finish the design and construction work.

Subject to parliamentary approval, the NCA expects costs, spend, and procurement of a builder will be complete by the end of this year, Mr Tallentine said. Works on the bridge will take place over 2024 and 2025.

The NCA states that traffic on surrounding roads would temporarily increase during construction. Construction vehicle movements are expected to peak during material delivery and during the main construction works. Some lanes would be closed and speed limits lowered for the safety of construction workers. A Traffic Management Plan would be developed to minimise delays to road and shared pedestrian and cycleway path users. Access over the lake would be maintained during construction.

The Commonwealth Bridge modernisation is not related to the ACT Government’s light rail stage 2A project, the NCA states, although both will take place at the same time. Raising London Circuit will be completed in 2024; and light rail stage 2A will be constructed between 2025 and 2027.w

Ms Barnes said the NCA would coordinate the Commonwealth Bridge project with the ACT Government’s light rail stage 2A. Light rail would not disrupt traffic on the bridge, she said.

“We’re working very closely with the ACT Government to minimise disruption, and have all these projects work together, but also keep the bridge open, make sure people can get to work, and continue to use the pedestrian path around the lake.”

Space has been saved for an independent bridge for light rail 2B (Commonwealth Park to Woden) constructed over Parkes Way between the two Commonwealth Avenue bridges.

• Have your say on light rail works approval (28 March 2023)

Ms Barnes acknowledged that Commonwealth Avenue would be busy for the next three to six years.

“But at the end of that process, the whole of Commonwealth Avenue, the bridge, the approaches, are going to be renewed, and look even more beautiful than they do today…

“If we don’t do it all together, we’ve missed the opportunity to renew this part of the city for the next 60 years.”

Pedal Power ACT

Pedal Power’s executive Director Simon Copland said the proposed designs would significantly increase active travel amenity on the bridge.

“We welcome the plan to increase the width of the shared path on Commonwealth Avenue Bridge to 5 metres,” Mr Copland said. “Commonwealth Avenue Bridge is an extremely busy cycling and pedestrian link, with people both using it to take a leisurely stroll or ride around the lake or for their daily commute.

“The current bridge footpath is too narrow, slowing cyclists down and creating often dangerous interactions between pedestrians and cyclists. The increased width of the shared path to 5 metres will significantly alleviate this problem. We also ask the NCA to ensure there are clear markers separating cyclists from pedestrians on this shared path.”

Pedal Power also welcomed the construction of new on and off ramps at the northern and southern ends of the bridge. 

“The proposed new on and off ramps will make it easier for both cyclists and pedestrians to access the bridge,” Mr Copland said. “The current ramps often do not meet accessibility standards, and we are pleased that the NCA is committed to undertaking work to fix these issues.

“However, cyclists will still face a series of missing infrastructure links when approaching the bridge, particularly on the western side from the north. Given this project, and the proposed works for Light Rail Stage 2a, this is the perfect time to fix these problems.”

Pedal Power said it would continue to participate in the consultation process.

“We have welcomed the engagement from the NCA on this project, and look forward to continuing working with them on these improvements as the project develops,” Mr Copland said.

“We encourage all bridge users to attend one of the NCAs consultation sessions and to provide their feedback on this plan.”