We've just received this pdf file from Transport for Wales (see below).
It's a newsletter outlining the work to take place in and around Radyr Station. There will be engineering work at night - which TfW reminds us can be noisy. But they promise to work with the local community to explain what they're doing and keep disruption to a minimum.
You can also take a virtual tour of the new trains TfW have commissioned, here (although we found the tour somewhat difficult to navigate).
TfW also told us:
We have started to build the South Wales Metro, a three quarters of a billion pound project that will make travelling easier, quicker and more convenient for us all in the future. In March this year, we took over the responsibility of the Aberdare, Coryton, Merthyr Tydfil, Rhymney and Treherbert lines from Network Rail. We are about to begin major work to upgrade them so that we can run more services than ever before on the new, faster, greener tram-trains we’re building. This major work starts in August and will continue until 2023.
While we build this better transport network over the next few years, it will mean temporary periods of change to rail passenger journey plans. Where possible, we are scheduling the transformation work to take place during less busy times to minimise disruption and offering connections between rail services and bus services.
The first phase of the transformation works starts on Monday 3 August 2020 with improvement work taking place on the Treherbert, Aberdare and Merthyr lines from Radyr station upwards. The work will take place late evening and overnight Sundays through to Thursdays during this period, with buses replacing trains on this part of the network from 2000 to 0500. Rail replacement services will operate from Radyr train station during this time.
Of course, at the current time, all our train services are only for key workers and essential travel, but we are asking people to plan ahead if they need to travel with us, as our travel advice is frequently being updated.
Over the coming years, together with our partners we’ll be:
A lot of the work on the railway will be done at night because our work either on, or very close to our railway lines can only be undertaken safely when trains aren’t running. We’ll endeavour to work responsibly, ensure our sites are well managed and that our people are considerate to our neighbours.
Here's the pdf file, in Welsh and English: