Parts of Birmingham city centre are to be pedestrianised in a radical rehaul of the city's roads.
The Paradise project, due to start on 5 January, will see the Paradise Circus Queensway underpass removed and traffic redirected.
Paradise Circus Queensway, which is currently one-way, will become a two-way route. Developers hope this will improve access for pedestrians.
Transport campaigners said the £500m scheme should improve the city centre.
The A38 underpass currently goes underneath the old library which is due to be demolished.
The first phase of the 10-year scheme, due to be completed in mid-2016, will see new public areas created, including a pedestrianised route to connect the Library of Birmingham to Chamberlain Square.
Developers said they wanted to make Birmingham "more like other big cities like Manchester" and give cyclists and pedestrians a better experience in the city.
They also said it would simplify the city for road users - although they admitted the road closure would initially cause disruption.
The project is being jointly funded by the city council and private funders, including the BT Pension Scheme, managed by Hermes Real Estate. A group called Argent is managing the development.
Chris Taylor, chief executive of Hermes Real Estate, said the work would "transform" the "civic, cultural and historic heart of the city".
Kevin Chapman, from the West Midlands Campaign for Better Transport, said there would be some "short-term pain" for commuters.
"Obviously, while the work is going on there will be disruption to traffic - bus services in particular," he said.
"But in the long term, it should offer improvements.
"It should make that whole Paradise area a lot more pedestrian-friendly. At the moment there are a lot of grim underpasses and it's not particularly great for walking.
"I know the council is aiming to move the city away from the concrete collar image we have had for 40 years. This work should help to achieve that."