SDLP MLA Daniel McCrossan has said work must begin immediately on the long-awaited A5 upgrade after reports it is expected to be approved by the Executive on Wednesday.
There have been more than 50 deaths on the road, which links Londonderry with Aughnacloy in Co Tyrone, since 2006.
A scheme to turn the road into a dual carriageway was first approved by the Executive in 2007 but it has been held up by legal challenges and uncertainty over funding.
Earlier this year, Infrastructure Minister John O’Dowd confirmed to the Assembly that he would be recommending that the planned upgrade of the A5 road should proceed.
BBC NI has reported that an announcement will be made on Wednesday and the work will be completed on a phased basis.
Mr McCrossan said approval from the Executive for the safety upgrade was a “momentous day” and that his thoughts are with the “families of everyone who has lost a loved one on this road”.
“This has been a very long journey – far too long – and their strength and courage has been a constant source of inspiration and we would never have seen this delivered without them,” he said.
“The campaign to build the A5 has been my number one priority throughout my time in politics and I have carried on the efforts of my SDLP predecessors in working with everyone to see these important upgrades carried out.
“Campaigners deserve huge credit for facing down every obstacle and making it absolutely clear they would not stop until people could safely travel on the A5.”
The West Tyrone MLA added that the Executive must provide assurances that the A5 will be delivered “in full”.
“We have seen repeatedly in the past how phased projects of this nature have stalled or been beset with delays,” he said.
“After such a long wait we need work to start – and finish – as soon as possible and I will not stop pushing this issue until these improvements are delivered and this road is fully built.”