The controversial proposal to demolish the Birchfield flyover in Perry Barr would cause two years worth of traffic disruption, it has emerged.
Ward representative Cllr Jon Hunt (Lib Dem) feared the temporary road diversions put in place would be inadequate.
He said: "We had a ward meeting where various people were talking about the big transport projects for Perry Barr including the proposed demolition of the flyover.
"Startling information came out of it (from a council officer) which is if they take out the flyover we would have two years of disruption on the roads because of the diversions put it.
"Frankly, local people have very little confidence that would be adequate.
"There would effectively be no access from the north, it would cut off a large chunk of the city."
The idea, which has not been approved at this stage, has been touted as part of the £523m regeneration of Perry Barr.
The main component of the project is to deliver the athletes village on the former Birmingham City University campus in time for the Commonwealth Games in 2022.
The site will accommodate more than 6,000 athletes and officials for the event and then provide 1,400 permanent homes afterwards.
But significant improvements to local transport infrastructure are needed.
The proposal to demolish the flyover, along with another idea to fill in the underpass further down at Aston Lane and Birchfield, was revealed in Birmingham City Council's outline business case for the regeneration scheme which was approved in June.
It said: "Highway redesign will include improvements to the Birchfield Road Roundabout with the provision of a new signalised junction together with the possible removal of the Birchfield Underpass.
"It will include changes to the Perry Barr Gyratory to reconfigure the A34 / A453 junction to remove traffic from the section of the A453 fronting the former Birmingham City University site, including the possible removal of the Birchfield Flyover."
More than 2,000 residents have opposed the idea via online and paper petitions.
At the moment officers are carrying out traffic modelling work and will present final options next year.
Other touted projects include the rapid Sprint bus route through Perry Barr, the new cycle lane on the A34 and redevelopment of the bus interchange and railway station.
Together, it is hoped the improvements will enable a further 1,600 homes to be built in the area.
A council spokesman said: “No decision on the future of the flyover has yet been made, so anything predicting the impact of any disruption caused by its removal is entirely speculative.
“The proposed Perry Barr regeneration scheme is an extremely important and long-awaited regeneration opportunity for the city, which will deliver much needed homes and better public transport for the citizens of Birmingham.
"With the construction of the residential element of the games village, the delivery of transport schemes and other related infrastructure work, some impacts are to be expected over the next two to three years as the development progresses.
“The council and Transport for West Midlands will be producing comprehensive construction management plans and implementing travel demand management to help mitigate any adverse impacts during the development period.
"This would include conditions within the planning consent where necessary.”
