Members of the inquiry team looking at plans to improve Cornwall's biggest traffic bottleneck meet for the first time on Friday.
The route is a notorious bottleneck
The pre-inquiry meeting into the notorious A30 road at Goss Moor, which is not open to the public, is being held at the Shire Hall in Bodmin.
Members of the inquiry team will scrutinise plans to upgrade the road.
They also aim to establish how the investigation should be run at the meeting.
But supporters of plans to bypass the area say the inquiry, which is being run by the Highways Agency, will simply delay action.
On the single lane stretch of road between two dualled sections, traffic jams on the moor can currently last for hours.
In October, £1.5m of European funding was secured to divert and widen the A30 around Goss Moor.
The EU cash will fund the restoration of the area after the work as well as linking other countryside to create one extensive nature reserve.