The Court of Appeal has overturned a High Court ruling that had blocked the A5 Western Transport Corridor dual carriageway scheme. The Department for Infrastructure (DfI) had appealed the earlier decision that quashed its authorisation to proceed with the first phase of the A5 WTC, a major road project linking Derry and Aughnacloy.

The appeal concerned four main issues: compliance with environmental impact assessment (EIA) requirements, human rights obligations, the Climate Change Act (NI) 2022, and the handling of evidence on climate change remittal. The Court of Appeal, comprising Lady Chief Justice Keegan, Lord Justice Treacy and Mr Justice Humphreys, found that the High Court had erred on all four grounds.

On the EIA issue, the court held that the environmental statement prepared for the project was adequate and that greenhouse gas emissions from induced cross-border travel had been properly assessed. The court found that the High Court had imposed too exacting a standard, effectively requiring a new environmental statement when the existing one met legal requirements. The Planning Appeals Commission had recommended publication of revised emissions estimates, which the DfI did, and the court ruled that further consultation was not legally required.

Regarding human rights, the High Court had found a procedural failure in the DfI's rejection of the PAC's recommendation to impose a time limit on the scheme's authorisation. The Court of Appeal disagreed, holding that the DfI had conducted a detailed human rights assessment and provided adequate reasons for departing from the recommendation. The court said the High Court judge had impermissibly stepped into the decision-maker's shoes.

The court also addressed the climate change challenge under section 52(1) of the Climate Change Act (NI) 2022, which requires departments to exercise functions consistently with emissions targets where possible. The court clarified that the Act does not require project-level emissions to be accounted for in a Climate Action Plan before approval. It found the DfI had sufficient information about emissions and policy pathways to rationally conclude the scheme was consistent with statutory targets.

The Court of Appeal concluded that the High Court's finding of an "evidential lacuna" rendering the decision irrational was wrong. The DfI had complied with its obligations, and the decision to proceed with the A5 WTC was lawful. The court allowed the appeal on all grounds.