100,000 vehicles a day would use new York Street Interchange in Belfast
It's Northern Ireland's busiest road junction - ferrying as many as 100,000 vehicles a day.
And proponents of the York Street Interchange scheme say this ambitious upgrade will be the final piece in the jigsaw that will allow traffic to flow freely from north to south and east to west in the city.
When the consultation was launched by then Roads Minister Danny Kennedy in January, the cost was estimated at between £125m and £165m and construction time at up to three years.
The minister said it would separate through traffic from the local streets by providing direct vehicle links between the Westlink, M2 and M3. Meanwhile, a new bridge would be constructed to carry York Street traffic over the junction.
Mr Kennedy said the design would take account of local residents' views, including fears that it could cut north Belfast off from the rest of the city.
Project manager Roy Spiers said the interchange will need foundations piled 40 metres deep, as it will be built on Belfast 'sleech' - a mixture of wet clay, silt and sand with the consistency of cold porridge - while the water table lies just below the surface.
If the plans go ahead as envisaged, traffic travelling from the Westlink to the M2 will pass under the new York Street bridge and then rise to join the M2 onslip.
Vehicles coming off the M2 will pass over Dock Street before dropping below ground level to reach the Westlink.
New single lanes swooping into underpasses will connect the Westlink and M3 in both directions. York Street itself will be raised on a bridge over the new underpasses.