The future of the A38 tunnels in Birmingham is being examined as part of a 20-year action plan to improve the city's transport network.
A council report said the tunnels created a "noisy unattractive barrier to intra-centre movement".
It said the network had coped better than anticipated when they were out of commission for six weeks in the summer.
Underground car parks and more cycle routes also feature in the Birmingham Mobility Action Plan (BMAP).
Calling for a debate on the long-term future of the tunnels, the report said: "There is no doubt the A38 provides a fast route across the centre for all traffic but it also severs the centre creating a very noisy unattractive barrier to intra-centre movement."
The BMAP report, which was produced by WSP Group for Birmingham City Council, said multi-storey car parks are unsightly and said one solution would be to replace them with underground car parks as in Paris and Lyon with parks and open spaces on top.
WSP associate director Simon Statham, citing the example of the Snow Hill car park, said the council could "sell that land to developers and get more money back than it would in car park revenue".
The report proposed investment in walking and cycling provision, including more than 350km (217 miles) of new or upgraded cycle routes.
By 2031 Birmingham's population is projected to grow by an additional 150,000 people, the report said. It said this could lead to 80,000 more cars in the city.
Birmingham City Council leader Sir Albert Bore, who launched the plan at Birmingham Town Hall on Thursday, said the tunnels would not close.
"It's not about closing them, it's about redesignating their use," he said.
"At the moment they are used as a through route. The question is 'should that be their long-term use'?
"You often get people weaving off at Great Charles Street and that often leads to an accident. We want to stop that weaving."
But one Birmingham resident, Darren Sunderland, 44, said he could not envisage the city without its tunnels.
"Birmingham is set up to have those tunnels," he said. "You are not going to change that. Underground car parks? It would never happen.
"The whole exercise sounds like a waste of money."
For Andy Hickman, a 54-year-old chef from Haig Street in West Bromwich, the action plan is a recognition that planners "need to do something".
But he said: "I'm not sure if Birmingham could cope without those tunnels.
"We survived over the summer when schools were closed but what about at peak times of the year?"