The Supreme Court in London is due to announce its decision on an appeal against the proposed Aberdeen bypass.
Campaigner group RoadSense has been fighting to stop the controversial £400m route which would join the A90 from Blackdog to Stonehaven.
The near 30-mile planned road, known as the Aberdeen Western Peripheral Route (AWPR), was given approval by Scottish ministers in 2009 following a public consultation which RoadSense claimed was flawed.
Two appeals against the final route by the group had previously been thrown out by judges in Scotland.
William Walton has led RoadSense as it has opposed the route.
Mr Walton’s legal team was headed by QC Aidan O'Neill, who led the legal team in the landmark Cadder case which secured the right of suspects in Scotland to have access to a solicitor in a police station.
The judgment is expected to be given at 9.45am on Wednesday.