- TNP Nation
- Ethnon
22 July 2026
TfW Class 756
Major rail upgrades as part of the South Wales Metro will take place this summer and rail passengers are being urged to check before they travel.
Essential rail upgrades to deliver faster and more frequent services will impact the South Wales Valley lines to and from Cardiff.
Work will be delivered from Saturday 25 July to Saturday 15 August across sections of the Rhymney, Coryton, Cardiff Bay, Treherbert, Aberdare and Merthyr lines.
This includes a 2-week closure across the Treherbert line and a one-week closure on the Aberdare and Merthyr lines.
To keep passengers moving, Transport for Wales will operate rail replacement buses throughout the blockade with full details, timetable and journey planning tools available at Metro service changes | Transport for Wales
The closure will allow Transport for Wales to carry out rail upgrades, relaying track at Pontypridd station, track and drainage improvements on the Treherbert line and level boarding at Pentrebach station.
Dan Tipper, TfW Chief Infrastructure Officer said: "These works are another important step in delivering the South Wales Metro and transforming rail travel across South Wales. While we know the closures will cause some disruption, the improvements we're making now will help create a more reliable, accessible and better-connected railway for the future.
"We’d like to thank customers and local communities for their patience while this vital work takes place. As rail services will be affected during the planned closures, we encourage customers to plan ahead and check the travel arrangements that will be in place for your journey, including any rail replacement bus services, and allow extra time for travel where necessary."
Services on other Valley lines will continue to operate to and from Cardiff via the City Line.
Rail replacement services will operate between Rhymney and Cardiff, and from Radyr to Cardiff stopping at Llandaf, Cathays and Cardiff Queen Street. On Saturday and Monday, Rhymney buses will run to and from Cardiff Queen Street with Bargoed replacement buses running to and from Cardiff Central.
Early-morning and late-night rail replacement services will run between Cardiff Central and Cardiff Bay, with ticket acceptance in place with Cardiff Bus throughout the day.
During the Treherbert, Aberdare and Merthyr line closures replacement buses will run every 30 minutes from Monday to Saturday and hourly on Sundays.
A small number of late-night services on Thursday 30 July and some early-morning services on Sunday 16 August between Pontypridd and Treherbert will be replaced by buses.
Ticketing
While rail replacement services are in place, passengers must hold a valid ticket before boarding. Pay as you go ticketing remains available, with validators positioned just a short walk from most replacement bus stops.
If a validator is unavailable, customers are advised to purchase their tickets via the TfW app or website or speak directly to members of the TfW revenue protection team who will be stationed at key locations across the network to assist.
Passengers with a pay as you go account who are unable to tap out, or who forget to do so, can also complete their journey through the TfW app or website the day after they travel by adding in a missed tap.
To provide additional reassurance to passengers using pay as you go, the number of tap corrections each user can do per month will be temporarily increased from 6 to 14 during the month of August.
As replacement buses may take longer than scheduled train services, passengers are strongly encouraged to check the latest travel updates on the TfW app or website and allow extra time for their journeys.
Engineering upgrades set for South Wales Metro this Summer
TfW Class 756
Major rail upgrades as part of the South Wales Metro will take place this summer and rail passengers are being urged to check before they travel.
Essential rail upgrades to deliver faster and more frequent services will impact the South Wales Valley lines to and from Cardiff.
Work will be delivered from Saturday 25 July to Saturday 15 August across sections of the Rhymney, Coryton, Cardiff Bay, Treherbert, Aberdare and Merthyr lines.
This includes a 2-week closure across the Treherbert line and a one-week closure on the Aberdare and Merthyr lines.
To keep passengers moving, Transport for Wales will operate rail replacement buses throughout the blockade with full details, timetable and journey planning tools available at Metro service changes | Transport for Wales
The closure will allow Transport for Wales to carry out rail upgrades, relaying track at Pontypridd station, track and drainage improvements on the Treherbert line and level boarding at Pentrebach station.
Dan Tipper, TfW Chief Infrastructure Officer said: "These works are another important step in delivering the South Wales Metro and transforming rail travel across South Wales. While we know the closures will cause some disruption, the improvements we're making now will help create a more reliable, accessible and better-connected railway for the future.
"We’d like to thank customers and local communities for their patience while this vital work takes place. As rail services will be affected during the planned closures, we encourage customers to plan ahead and check the travel arrangements that will be in place for your journey, including any rail replacement bus services, and allow extra time for travel where necessary."
- Cardiff Queen Street | Saturday 25 July - end of service Monday 27 July
Services on other Valley lines will continue to operate to and from Cardiff via the City Line.
Rail replacement services will operate between Rhymney and Cardiff, and from Radyr to Cardiff stopping at Llandaf, Cathays and Cardiff Queen Street. On Saturday and Monday, Rhymney buses will run to and from Cardiff Queen Street with Bargoed replacement buses running to and from Cardiff Central.
Early-morning and late-night rail replacement services will run between Cardiff Central and Cardiff Bay, with ticket acceptance in place with Cardiff Bus throughout the day.
- Treherbert line - Pontypridd | Friday 31 July - Thursday 6 August
- Treherbert / Aberdare / Merthyr - Radyr | Friday 7 August - Saturday 15 August
During the Treherbert, Aberdare and Merthyr line closures replacement buses will run every 30 minutes from Monday to Saturday and hourly on Sundays.
A small number of late-night services on Thursday 30 July and some early-morning services on Sunday 16 August between Pontypridd and Treherbert will be replaced by buses.
- Due to local road restrictions, the main replacement bus service along the Aberdare line will not call at Penrhiwceiber. To keep passengers moving, a dedicated minibus shuttle service will operate between Abercynon, Penrhiwceiber, and Mountain Ash.
- To accommodate rail replacement services, the car park at Radyr station will be temporarily closed from Monday 3 August. Customers are asked not to park on nearby residential streets and are encouraged to use alternative car parks across the network, including Llandaf, Taff's Well, Trefforest and Abercynon.
Ticketing
While rail replacement services are in place, passengers must hold a valid ticket before boarding. Pay as you go ticketing remains available, with validators positioned just a short walk from most replacement bus stops.
If a validator is unavailable, customers are advised to purchase their tickets via the TfW app or website or speak directly to members of the TfW revenue protection team who will be stationed at key locations across the network to assist.
Passengers with a pay as you go account who are unable to tap out, or who forget to do so, can also complete their journey through the TfW app or website the day after they travel by adding in a missed tap.
To provide additional reassurance to passengers using pay as you go, the number of tap corrections each user can do per month will be temporarily increased from 6 to 14 during the month of August.
As replacement buses may take longer than scheduled train services, passengers are strongly encouraged to check the latest travel updates on the TfW app or website and allow extra time for their journeys.