First official walk-through of new Tyne Tunnel
The first official walk-through of a new £260m road tunnel under the River Tyne is due to take place later.
MPs and civic dignitaries from North and South Tyneside have been invited to the event.
It will be the first time anyone other than project workers have been permitted inside the structure.
The new Tyne Tunnel, which links North and South Tyneside, is due to open in February 2011, when the existing tunnel will close for refurbishment.
The final section of the crossing was excavated in May when workers broke through the last concrete wall.
Trevor Jackson, managing director of contractors TT2, said: "To be able to walk from one end of the land tunnel to the other beneath Jarrow really gives a sense of achievement and brings us one step closer to opening the new tunnel to traffic.
"This is a tremendous moment for everyone involved in the project."
David Wood, chair of the Tyne and Wear Integrated Transport Authority, added: "It is incredible to think that the first dig to create the tunnel trench happened around a year and a half ago.
"The process has gone very smoothly and I am delighted with progress."
The existing tunnel, which opened in 1967, carries more than 11 million vehicles a year.
The new tunnel has been built east of the existing site between Jarrow in South Tyneside and Howden in North Tyneside.