Last updated: 23 June 2017

Where & Why?

Essential safety refurbishment works of the M4 Newport Brynglas Tunnels will commence Monday 20th June 2016 and continuing until February 2018.

The refurbishment of the tunnels is required to upgrade the Mechanical and Electrical (M&E) systems, as well as the carriageways, drainage and tunnel linings in order to provide resilience in the tunnel systems for the foreseeable future.

Routine essential maintenance such as tunnel cleaning will continue to be undertaken while the refurbishment works are in progress.

Diversions & Safety Measures

The M4 will be closed between junctions 25A and 26 from 8pm to 6am on up to five nights per week. The A48 Southern Distributor Road in Newport is the dedicated diversion route for all eastbound or westbound traffic. The diversion will be in place between junctions 24 and 28 of the M4; however, local traffic will be allowed to travel up to junctions 25a and 26 in order to access local routes. Closures will usually be in place in one direction at a time; however, closure of both tunnel bores may be needed for short periods of time for safety reasons.

Slip roads leaving and joining the M4 at junction 26 (Malpas) will also be subject to overnight closures. These closures will be restricted to only one slip road at any one time. During any night-time closure of any of these slip roads the motorway will remain in normal operation in both directions.

The current planned closure dates for tunnel refurbishment works and routine maintenance are listed below. Dates may be subject to change for various reasons, such as weather conditions. Additional closures may be required in emergency situations. Latest planned dates and times will be updated in our Home page map, Travel Menu, smartphone apps, Twitter feed @TrafficWalesS or will available by calling us on 0300 123 1213.

 

WEEKNIGHT CLOSURES:

Direction of tunnel closure

First date of closure Last date of closure Closure timings Main purpose
Westbound Tuesday 02/05/17 6am Thursday 20/07/17 Closures 8pm-6am on weeknights Mondays to Fridays only Tunnel refurbishment works
J26 Westbound Off-slip Monday 26/06/17 Friday 30/06/17

Monday to Friday, 24 hours

Daytime diversion:
Continue westbound to J27, join M4 eastbound, exit at J26.

Night-time diversion:
Full tunnel closure in place. Local traffic exit J25a.

Tunnel refurbishment works
J26 Eastbound Off-slip Monday 26/06/17 Friday 07/07/17

Closures 8pm-6am on weeknights Mondays to Fridays only

Diversion: Continue eastbound to J24, join westbound and exit J25a.

Tunnel refurbishment works
J26 Eastbound On-slip Monday 10/07/17 Friday 14/07/17

Monday to Friday, 24 hours.

Diversions:
M4 – at J26 take M4 westbound to J27 and join M4 eastbound.

Pontypool / Cwmbran eastbound traffic - follow A4042 southbound to join M4 eastbound at J25a.

Tunnel refurbishment works
Eastbound Thursday 20/07/17 6am Saturday 22/07/17 Closures 8pm-6am on weeknights Mondays to Fridays only Tunnel refurbishment works
Westbound Monday 24/07/17 6am Saturday 19/08/17 Closures 8pm-6am on weeknights Mondays to Fridays only Tunnel refurbishment works
Eastbound Monday 21/08/17 6am Thursday 11/01/18 Closures 8pm-6am on weeknights Mondays to Fridays only Tunnel refurbishment works
Westbound Thursday 11/01/18 6am Thursday 15/03/18 Closures 8pm-6am on weeknights Mondays to Fridays only Tunnel refurbishment works

 

WEEKEND CLOSURES:

Direction of tunnel closure

First date of closure Last date of closure Closure timings Main purpose
Westbound Saturday 01/07/17 Monday 03/07/17 Closed from Saturday 8pm until Monday 6am Tunnel refurbishment works
Westbound Saturday 15/07/17 Monday 17/07/17 Closed from Saturday 8pm until Monday 6am Tunnel refurbishment works
Eastbound Saturday 16/09/17 Monday 18/09/17 Closed from Saturday 8pm until Monday 6am Tunnel refurbishment works
Eastbound Saturday 23/09/17 Monday 25/09/17 Closed from Saturday 8pm until Monday 6am Tunnel refurbishment works
Eastbound Saturday 07/10/17 Monday 09/10/17 Closed from Saturday 8pm until Monday 6am Tunnel refurbishment works

 

Enquiries

Further scheme information is available from the Welsh Government website:
http://gov.wales/topics/transport/roads/schemes/m4/brynglas-tunnels/?lang=en (external link).

Latest planned dates and times will be updated in our Home page map, Travel Menu, smartphone apps, Twitter feed @TrafficWalesS or will be available by calling Traffic Wales on 0300 123 1213.