The Canberra Liberals have conceded a key part of their public transport alternative to a Woden light rail extension would be near impossible to build.
The party's promised transit lane to speed up buses all the way between the city centre at Woden could not include Commonwealth Avenue bridge.
Mark Parton, the opposition's transport spokesman, wrote on X that it was unlikely a dedicated bus lane would be built on the bridge.
"At the time it was not clear to us whether the NCA bridge renewal would provide an additional transport lane. That's not going to happen, so it's not likely that there will be a dedicated bus lane on the bridge," Mr Parton wrote from his account.
Mr Parton said in a subsequent post on the platform, formerly known as Twitter, that he was focused on transport outcomes and believed the Liberals could achieve them.
Transport Minister Chris Steel said the Liberals had admitted a key policy did not work and questions remained how they could remove northbound lanes from Capital Circle to Coronation Drive without increasing congestion on Adelaide Avenue.
"The Liberals B-grade bus plan was always light on detail but it has now failed the most basic scrutiny," Mr Steel said.
"Unlike buses, light rail will run on its own dedicated bridge adding significant capacity to this key North-South transport link, which will become more congested as the city grows.
"With four months until the election the Liberals now have no plan for public transport on the southside."
A new bridge for light rail, to be built between the two existing spans of Commonwealth Avenue bridge, would have the capacity to move 2500 people an hour, up from an estimated 1100 people an hour per road lane.
The Commonwealth Avenue bridge is due to be widened as part of a package of works planned by the National Capital Authority.
In April 2023, the National Capital Authority released early plans for the works, which included widening shared paths but not adding any extra transit lanes.
In March 2024, the Canberra Liberals released a transport policy that included a map of what it called "The future City to Woden transport corridor". The corridor included a "new bus lane" on Commonwealth Avenue bridge.
A spokesman for the Canberra Liberals on Sunday said the final design of the party's policy would be determined if they formed government after the October 19 election.
"The Canberra Liberals in government will deliver Woden to Civic bus journey times that are approximately twice as fast as the proposed tram for a fraction of the cost. This will be achieved through a series of measures including dedicated bus lanes and bus priority at traffic lights, the final design of which will be fully scoped in government," the spokesman said.
"The government has a $100 million contract with AECOM for stage 2B of the tram to undertake this very work and yet they still don't have a final design and aspects of their plan continually change."
The Liberals' policy did not say whether a bus lane on Commonwealth Avenue bridge would replace a lane for general traffic.
The city to the Woden bus corridor would be completed by 2027 and cost about $70 million, the party said at the time. The proposal would be completed before work is scheduled to begin on the Woden light rail extension, and include intersection priority for bus traffic, the Liberals said.
Public Transport Association of Canberra chair Ryan Hemsley said there was no credible alternative to light rail.
"The idea of a busway as a substitute for light rail was always wishful thinking and a second-rate solution. Our growing city needs real mass transit to do the heavy lifting. This is why we need to extend our successful light rail network across the lake," Mr Hemsley said.
Mr Hemsley said it was alarming the opposition had released a policy it knew could never be implemented.
"They need to be honest with Canberrans and stop pretending their plans would come anywhere close to delivering the same benefits as light rail," he said.
Light rail to Woden is due to be completed in 2033, the government announced in February. The Canberra Liberals have claimed the project would cost more than $4 billion; the government has declined to set a price for the project, citing future sensitive commercial negotiations.
The ACT government on Friday revealed a cut-and-cover tunnel would connect the light rail line between Commonwealth Avenue and State Circle in the latest plan to overcome the challenges of the preferred route.
Planners are confident they can overcome the challenges of the State Circle route to run light rail past Parliament House, and avoid the need for the so-called Barton "dog leg" along parts of National Circuit.
