Start date: 18/07/2025| End date: 30/08/2025
Work to carry out a full bridge deck refurbishment to the M4 Maes Y Gwernen Overbridge will commence on 18 July for six weeks.
A full road closure on the M4 Maes Y Gwernen overbridge will be required whilst the works are being carried out.
This essential work will be carried out over the Summer holidays to reduce impact on Morriston Comprehensive School.
A full overnight road closure of the M4 carriageway will be required to inspect the underside of the overbridge on the following dates between the hours of 20:00 - 06:00:
11/08/25 - 13/08/25
Westbound closed between J45 Ynysforgan - J46 Llangyfelach.
Lane 2 closed eastbound.
13/08/25 - 15/08/25
Eastbound closed between J46 Llangyfelach - J45 Ynysforgan.
Lane 2 closed westbound.
15/08/25 - 16/08/25
Junction 45 westbound entry slip road closed.
Lane 1 closed in both directions.
Motorway Traffic Diversion
North Side of Overbridge: Traffic diverted via Heol Maes Eglwys to Pant Lasau Road, Then join the M4 at Junction 46 (Llangyfelach Interchange).
South Side of Overbridge: Traffic diverted via Llanllienwen Road, Then join the M4 at Junction 45 (Ynysforgan Interchange).
Local Traffic Diversion North Side of Overbridge: Traffic diverted via Heol Maes Eglwys to Pant Lasau Road, then join the A48 and A4067 southbound. At the Ynysforgan Interchange, exit via Llanllienwen Road.
South Side of Overbridge: Traffic diverted via Llanllienwen Road, Then take A4067 southbound to join the A48. Use Pant Lasau Road to reach local destinations on the north side.
Pedestrians South Side of Overbridge: Pedestrians will be diverted to Maes Y Gwernen Road to use the Morriston hospital footbridge, to connect to Heol Maes Eglwys Road and Rhodfa Fadog Road.
North Side of Overbridge: Pedestrians will be diverted along Heol Maes Eglwys Road to use the Morriston hospital footbridge, to connect to Heol Y Gwernen Road.
M4 Carriageway Closure Diversion (11/08/25 - 15/08/25)