High Court judge Mr Justice McAlinden is due to deliver his ruling on the future of the A5 road scheme later today.
The 58-mile project was given the green light by Stormont ministers in October 2024.
However, the following month a group of residents and landowners began judicial review proceedings – Hassard v Department for Infrastructure – against the £1.2bn dual carriageway upgrade.
Preparation work had already started on parts of the long-delayed road scheme and in March this year the infrastructure minister visited a location where some advance works were under way.
More than 50 people have died on the A5 since 2006 and campaigners have called for the road to be upgraded.
The scheme was first announced back in 2007, but has been beset by a number of delays.
A group of local residents, landowners and farmers mounted a fresh challenge against the decision to begin construction work.
The umbrella group, known as the Alternative A5 Alliance, contended it would breach legislative targets set out in NI’s Climate Change Act 2022 to achieve net-zero greenhouse gas emissions by 2050.
Part of the case centred on Planning Appeals Commission recommendations against proceeding with the scheme unless the DfI was satisfied it would not undermine those goals.