Drivers in Wales are being warned to expect severe road traffic as train passengers take to their cars during the rail strikes.
Most railway lines in Wales will be closed during the industrial action on Tuesday (June 21), Thursday (June 23) and Saturday (June 25), prompting a warning that motorists could face long queues.
The AA predicts some the worst affected roads in Wales will be the M4, A55, A5, and A483.
'Many travellers will give up on the trains for the whole week'
An AA route planner spokesman said: “Even though the strike is for three days, many travellers will give up on the trains for the whole week.
“It coincides with big events like Glastonbury and the Goodwood Festival of Speed, so drivers not going to those locations are advised to give the areas a wide berth.
“Generally we predict a big increase in traffic in Scotland, Wales and major routes across the UK.
“The impact will be slightly cushioned by record fuel prices deterring some and more commuters deciding to work from home but congestion will still be a problem.”
Which rail services will still be operating?
The only train services running in Wales on 21 and 23 June will be a reduced service between Radyr and Treherbert, Aberdare and Merthyr Tydfil, with replacement bus services between Radyr and Cardiff Central.
On 25 June, this will be reduced further to services between Radyr and Treherbert, Aberdare and Pontypridd, with replacement buses in operation between Radyr and Cardiff Central, and between Pontypridd and Merthyr Tydfil due to the ongoing transformation work for the South Wales Metro.
All other services will be suspended, as signalling and other infrastructure work is managed by Network Rail, who are impacted by the industrial action.
There is also expected to be disruption on the days prior and after the industrial action, with early morning services in particular likely to be affected. Trains are also expected to be extremely busy throughout the entire week.
Do not travel warning
Transport for Wales is advising customers only to make essential journeys by train on 20, 22, 24 and 26 June, and not to travel at all by train on 21, 23 and 25 June.
Full details of the timetable for these days can be found on the Transport for Wales, Traveline and National Rail websites using the journey planners.
Why are the strikes happening?
Union members voted overwhelmingly for action in growing rows over pay and job losses.
The RMT said rail staff who worked through the Covid-19 pandemic were facing pay freezes and hundreds of job cuts.
Grant Shapps, the UK government's Transport Secretary, described the strike action as "incredibly disappointing", arguing that the pandemic had changed travel habits with 25% fewer ticket sales.