M8 J29A Southbar Interchange

Scheme outline

Re-opening of Southbar interchange (closed in the 1970s) connecting the M8 to the A8 between junctions 29 and 30. The layout of the new junction will be significantly different to the original; two new roundabouts will be provided on the A8 with two sliproads accessing the motorway to and from Glasgow. No access will be provided to or from the north.

The original junction had free-flowing sliproads to and from Glasgow, with a large loop in the north-east quadrant. These will not be reinstated. The land once occupied by the loop is no longer owned by Transport Scotland and the new interchange will involve acquiring much less new land than if the original junction were to be rebuilt.

The junction is required to support extensive regeneration plans around Bishopton, including construction of a major new BAE facility.

This scheme was completed in and we're no longer accepting updates or changes to this page.

Junction improvement
under motorway restrictions
Highway authority
Scottish Government


3 May 2017

Earth moving has now started on site.

21 August 2017

Ground works and drainage for slip roads in both directions progressing. At the present time, levelling of the slip road grounds are underway and the routes are starting to gain definition although the locations of the new roundabouts are unclear.

On the M8 east and west carriageways, there are concrete protection barriers separating traffic from the work area. It's currently unclear when surfacing and linking of the slip roads will commence. Local rumour suggests that work will complete well ahead of schedule but then be mothballed until the new Dargavel Village estate reaches a certain occupancy level that will activate the road opening. For now rush hour tailbacks exist with traffic using the same slip road to access the Erskine Bridge approach and the Bishopton / Erskine exit.

Local feeling is that the new west bound slip road is too close to the existing exit and the same tailbacks will occur unless the M8 is widened with at least one long additional slip lane to alleviate the pressure.

8 December 2019

The junction opened to traffic on Friday 6th December.

More information