A5 project: The road 13 years in the making but still in limbo

The A5 dual carriageway scheme would link Dublin to the north west of Northern Ireland

It's Northern Ireland's biggest ever road project - but will it get back on track after a new public inquiry?

The long-awaited A5 project was first put forward in 2007, but has been beset by funding issues and legal challenges.

The inquiry will begin in Omagh, County Tyrone, on Tuesday looking at the environmental impact of the proposal.

A protest group, Alternative A5 Alliance, have previously launched two legal challenges against the project.

Speaking about the further hearing, roads expert Wesley Johnston said the saga had become "like Groundhog Day".

"At a total cost of £1.1bn, this is by far the largest, single roads scheme ever envisaged here, dwarfing even the motorway schemes of the 1960s and early 1970s," said Mr Johnston.

The A5 Western Transport Corridor (A5WTC) is a planned road project linking counties Londonderry and Tyrone.

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The proposed scheme involves 85km (53 miles) of new trunk road between Newbuildings, outside of Londonderry, and Aughnacloy in County Tyrone.

The project was split into phases, with construction of phase one (Newbuildings toward Strabane) due to begin in 2018.

But work never commenced.

Why has it been delayed?

The project has been met with criticism from Alternative A5 Alliance (AA5A).

The campaign group - made up of farmers, landowners and others with an interest in the County Tyrone area - oppose the compulsory purchase of land to construct the road and have raised environmental issues around the project.

Their last legal challenge, in 2018, resulted in the Department for Infrastructure (DfI) quashing plans to proceed.

Wesley Johnston said the department have found themselves in a "Groundhog Day scenario".

The project has been met with criticism from Alternative A5 Alliance (AA5A)

This is because their environmental documents "have to be both complete and up-to-date", but "the more complete they are, the longer they take to produce and hence the more out-of-date they are, and therefore more susceptible to legal challenge".

He added: "Even unsuccessful legal challenges delay the scheme enough to require the environmental documents to be re-done."

Órfhlaith Begley, Sinn Féin MP for West Tyrone, has said ongoing delays have been "deeply frustrating".

"Progress on this vital piece of infrastructure has been delayed over the past decade by repeated legal challenges by an unrepresentative minority group," she said.

Órfhlaith Begley hopes the public inquiry will allow the project to "proceed with haste"

"Therefore it is vital that all parties who vow support for the A5, now step up to the plate and it is crucial that the majority voice for the A5 is fully reflected at this upcoming public inquiry."

Ms Begley said more unnecessary delays "will ultimately result in commuters' lives being put at risk".

"All efforts must be made to ensure there are no more fatal accidents on this road," she added.

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John Dunbar, chair of the Alternative A5 Alliance, said the group would continue to object to the plans "which are contrary to the common sense needs" of the people who live in, and visit, the area.

He said the road "flies in the face of the stated policy of encouraging greater use of public transport".

"We implore the Department of Infrastructure to take that leap of faith and replace the proposed road scheme with the re-instatement of the railway and at the same time upgrade the existing A5 road with additional passing opportunities and other affordable general improvements," he said.

"This approach will go a long way to relieving the stress of upwards of 300 farmers and property owners who, for the past decade or more, have had their properties blighted by the threat to carve a great chunk of some 3,000 acres of farmland along the path of the A5."

In a statement, the DfI said: "Following the quashing of the decision to proceed with the A5WTC scheme in late 2018, the department has been working to complete steps to enable a fresh decision on this NI Executive flagship project."

The inquiry, at the Strule Arts Centre in Omagh, will discuss the possibility of road work affecting air quality, cultural heritage, landscape and visual effects.

Supporters of the project are hoping, with a new power-sharing executive in place, it can finally move forward.

However, opposition to the project still remains and further delays may be likely.