A public inquiry into the upgrade of a road, described as the most dangerous on the island of Ireland, has opened in Omagh.
Families of those killed on the A5 gathered outside the Strule Arts Centre ahead of the inquiry on Monday.
Campaigners say 47 people have died since 2007 when the project was given the go ahead.
Kevin McCloughan, whose 19-year-old son Maurice died on A5 road in 2016, said they hope action will take place "as soon as possible".
He said: "The outcome, obviously to get it started and as soon as possible - we are here to support it that it should be done as soon as possible to stop another.
"We had a meeting there last week - 47 people have lost their lives don't want to be 40 never mind 50, don't want it to be 48 or 49."
Relatives of Dan and Christine McKane, and their aunt Julia McSorley, have backed the campaign to make the road safer.
The A5 road project connects Londonderry to the Irish border at Aughnacloy. Both the UK and Irish governments have pledged millions in support to build the road.
Upgrade work is intended to improve access to Dublin and safety. An investigation found it would benefit journey times and economic competitiveness.
However, it has faced delays due to concerns over flood risk, environmental and cultural impact as well as noise.
The 'Enough is Enough' campaign group is calling for the upgrade. It says 47 people have been killed since the project was given the go ahead by the Assembly in 2007.
A protest was held outside the Strule Arts Centre ahead of the inquiry starting. Families of those who have lost loved ones gathered.
Meanwhile the Alternative A5 Alliance group, which opposes the scheme, says many of its members would be "seriously and adversely affected".
A statement said: "The Alternative A5 Alliance opposes this scheme and contends that it is overprovision and there are more proportionate alternatives to the proposed new offline dual carriageway and these should have been fully appraised and costed."
The commissioner for the inquiry, Gareth Kerr, said he hopes to make "clear and robust recommendations and bring this saga to an end".
Mr Kerr said this had been trapped by delays for over a decade.
In opening remarks he said: "We are painfully aware that the A5 scheme has been trapped for more than a decade in a cycle of information gathering, public consultation and abortive decision making.
"We intend to present the department with clear, robust recommendations on all key issues so that it can make and implement firm decisions and bring this saga to an end.
"On the final day, I will indicate approximately when we expect to deliver our report to the department."
The inquiry is set to sit for two weeks.
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