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The Welsh Government’s traffic information service for motorways and trunk roads in Wales

A470 Nant Garw Interchange - Underbridges (North and South)

Where and Why?

These are essential highway maintenance works and comprise the refurbishment and repair of the existing underbridges. These works include a number of remedial measures including but not limited to:

(i)    Concrete Repair of the bridge deck;
(ii)    Waterproofing the top surface of the bridge deck;
(iii)    Resurfacing sections of carriageway; 
(iv)    Replacing deteriorated components.

Diversions and Safety Measures

Works will be undertaken over five weeks. The main works will be undertaken over 2 consecutive weekends on each carriageway. 
Works will commence on Monday 14th September and be completed by the 14th October. 

The works on the carriageway will initially be undertaken during off peak times between the hours of 8pm and 6am utilising lane and full carriageway closures. 

During the weekend, works will commence at 8pm on the Friday and will continue until 6am on Monday.  These works will commence with full carriageway closures of the northbound and/or southbound carriageways. During the weekend, traffic will be operating under contraflow; some slip roads will be closed. Signed local diversions will be in place and advance notification signs will be provided. Further updates will be provided if required. 

Programme of Traffic Management restrictions

Week 1

  • Monday 14th September to Friday 18th September 2020- night, NB/SB Lane 2 closures

 Week 2

  • Sunday 20th September to Monday 21st September  night, NB/SB closures*  
  • Friday 25th September  – night NB and SB closure*
  • Saturday 26th September to Sunday 27th September – Contraflow on SB carriageway   
  • Sunday 27th September – night NB and SB closure*

Week 3

  • Monday 28th September to Tuesday 29th September – night NB closure*  
  •  Wednesday 30th September to Thursday 1st October  - night SB closure* 
  •  Friday 2nd October – night NB and SB closure*
  • Saturday 3rd October to Sunday 4th October – Contraflow on NB carriageway   
  • Sunday 4th October – night NB and SB closure*

Week 4

  • Monday 5th October to Tuesday 6th October – night SB closure*  
  • Wednesday 7th October to 9th October - night NB and SB closure*

Week 5

  • Monday 12th October to Wednesday 14th October - night, NB/SB Lane 2 closures

* Northbound (NB) closures are from Taffs Well; Southbound (SB)  closures are from Bridge Street
**Please note, programme could be subject to change


For further information, please contact Traffic Wales on 0300 123 1213 or via Twitter @TrafficWalesS.

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