Northern Ireland's biggest-ever roads project has run into a few barriers along the way.
But, until now, governments on either side of the border have insisted there won't be any U-turns on the £800m A5 dualling scheme - and both intend to honour the funding they have pledged.
But now voices of dissent are being heard both north and south, with Irish Labour Party TD Joe Costello warning that his government's €470m contribution to upgrading the A5 and A8 must be rethought under the current economic crisis.
Construction work on the A5 is due to start in 2012 and the project is subject to finance being made available and the outcome of a public inquiry next year.
The scheme would see the existing A5 between Londonderry and Aughnacloy upgraded to a dual carriageway, shaving 20 minutes off the journey-time from Derry to Dublin.
But campaigners opposed to the A5 dualling scheme say a 2+1 scheme, with overtaking lanes, would be more appropriate.
They warn that valuable farmland will be lost and communities will be cut in two because there are only eight access points.
Mr Costello warned that there is also a question mark over the Republic's ability to build the Aughnacloy-to-Dublin road.
"Already major projects are tumbling in my own constituency and, in that context, we cannot exempt any project," he said.
"I am not saying we will abandon the project, but it will have to be reviewed very carefully considering the financial straits we are in at this present time."
In the wake of Costello's comments, Ulster Unionist leader Tom Elliott warned that it would be "sheer folly" to press ahead with the A5 until a new government has been formed in the Republic.
"There simply would be no justification on spending more money on the new Londonderry-to-Aughnacloy road if there is no new road on the southern side of the border," he said.
"I am suggesting the whole project must be reviewed - especially given that there may be early elections in the Irish Republic."
But the DRD remains steadfast, insisting: "The revised budget from the Irish government has given a commitment that, as agreed, part-funding for both the A5 and A8 major road schemes is now guaranteed and the [Northern Ireland] Executive expect that to be honoured."