Several hundred people have taken part in a rally in support of the A5 road scheme.
The group, which included the relatives of people killed in crashes on the road, gathered at the High Court in Belfast where an appeal against the development began on Tuesday.
The 58-mile (94km) £1.2bn project was given the green light by then Infrastructure Minister John O’Dowd in October 2024.
The following month a group of residents and landowners began judicial review proceedings against the dual carriageway scheme.
More than 50 people have died on the A5 since 2006 and campaigners have demanded improvements be carried out.
The scheme was first announced back in 2007, but has been beset by a number of delays.
The A5 is a vital artery of the Northern Ireland road network. More than 58 miles (94km) long, it has more than 200 side roads connecting to it.
The road is single carriageway for most of its length, with overtaking lanes in some sections.
It links Londonerry with Aughnacloy in County Tyrone and passes through towns like Sion Mills, Omagh and Strabane.
It is the main north-south route in the west of Northern Ireland, providing a link between County Donegal and Dublin, via the N2 in County Monaghan.
The road has remained largely unchanged since the 1960s, with the exception of some town bypasses, but there has been a huge rise in the number of cars, lorries and agricultural vehicles using it since it was first built.
Official statistics show there has been about a 10% increase in traffic on the road in the last 10 years alone. An increase of about 30% is forecast over the next 25 years.
