M4 Widening J29-32

Scheme outline

On-line widening of the M4 between junctions 29 and 32 (the Cardiff bypass section) to dual-three lane motorway. The scheme was procured under an 'Early Contractor Involvement' contract. The Works are being administered under the NEC 2nd Edition Option C - an old version of the New Engineering Contract. The contractor carrying out the works will get a modest bonus for finishing on time and on budget but will be fined if they overspend.

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

Other upgrade
under motorway restrictions
Highway authority
Welsh Assembly Government


14 March 2007

Site clearance started in January. Most verges and banks have now been cleared of vegetation and a site compound has been set up north of junction 30.

14 May 2007

Site has now been cleared and construction of strengthened hard shoulders is nearly complete.

14 June 2007

A contraflow is in use to allow work on the eastbound carriageway.

14 March 2008

Traffic is able to use two lanes of the widened eastbound carriageway between junctions 30 and 32 while work is under way on the central reservation. Earthworks are in progress between 29 and 30, while ground clearance is taking place near junction 29.

9 November 2008

By 24 November Phase 1 (junctions 30 to 32) of the works will be completed. Phase 2 (junctions 29 to 30) will follow on.

7 September 2010

The opening ceremony took place on 25 January 2010.

More information