One capital city's major bridge may require a $1 billion makeover after a report issued a dire warning about the 85-year-old structure's future.
Brisbane's Story Bridge - opened in July 1940 - is deteriorating as it bears the weight of an unprecedented volume of traffic and may close in 20 years if action isn't taken, a council report has revealed.
The Brisbane City Council probe found that access to the bridge for pedestrians, cars, buses and trucks would become increasingly restricted unless the structure was restored.
Footpaths have already been closed in the wake of Tropical Cyclone Alfred after assessments showed they have deteriorated at an accelerated pace.
The river city is less than eight years away from hosting the 2032 Olympics and the bridge in its current condition won't be able to cope with increased usage.
This means it will have a restricted capacity during the Games, the report found.
Unless steel frames, rusted bolts and corroded connections are fixed, public transport and freight would have to be removed by 2035, it said.
The report also claimed cars and tourism activity would be restricted by 2040 and the bridge would be closed and demolished by 2045.
A transport expert says the major restoration could cost up to $1 billion, with the bill to ultimately fall on the federal government.
"In the three-tiered system in Australia, the Commonwealth government has the money, the state government has most of the powers, and the local governments just have the problems," Griffith University's Matthew Burke told AAP.
Professor Burke said this wasn't just a Brisbane problem, but there would be ageing infrastructure assets nationwide that would weigh on the federal government's bottom line.
Brisbane City Council has called on the state and federal governments to help foot the bill for the bridge after already forking out $120 million over the past 20 years, in addition to $3 million annually to maintain the structure.
Alternatively, the council report proposed introducing a toll on the bridge for the first time since 1947 to help fund restoration efforts, but it said that should be a last resort.
It could also create a voluntary special rates levy for residents to contribute to the restoration or explore a corporate sponsorship.
Deputy Premier Jarrod Bleijie said the council needed to put in a formal request for additional funding but it was ultimately the local government's asset.
The council will proceed with a business case for the best way to restore the bridge, with multiple options to be considered, including a short, sharp plan over seven years to fix the structure before the Olympics.
It could also take 15 years if that was more cost-effective, Lord Mayor Adrian Schrinner said.
Prof Burke said it was unlikely the bridge would be fixed by 2032 and expected the city to resort to reducing traffic in the city by closing schools and universities, and encouraging office workers to stay home.
Regardless of when the restoration is completed, it will remain a big shock for commuters when works begin, with the bridge to be closed for months, he said.