Just five train services are running in Wales as the rail strikes enter a third day.
Passengers in Wales have been affected as thousands of frontline rail staff strike again with no trains west of Cardiff or north of Merthyr Tydfil.
Routes that are running, including the south Wales to London main line, are running a reduced service as less than 10% of the network in Wales operates.
Travellers are also being affected by the M48 Severn Bridge weekend closure.
About 50 people have taken part in a protest in Cardiff in support of RMT members.
Trains started at 07:30 BST and finish at 18:30 across most of the rail network on days of industrial action, which were called by the RMT union after talks over pay and redundancies fell through.
A special timetable has been published and Network Rail has said passengers should travel by train only if necessary.
Rail companies have also warned passengers that journeys on Sunday and even Monday could be affected by the walkout.
The expected knock-on disruption is because of too few staff working overnight and morning shifts not clocking on until after the usual morning timetable has begun.
What trains are running on strike days in Wales?
On the south Wales to London mainline, there are just nine trains running in each direction, but trains are operating only from Cardiff Central. Stations between the Welsh capital and Swansea have no services.
Those direct GWR services between London Paddington and Cardiff will be one an hour, not the usual two, with the first service leaving each terminus later than normal.
A service between Cardiff and Westbury in Wiltshire - linking south Wales with Bristol and Bath - also ran a reduced service.
The only other trains operating in Wales are valley line services from Treherbert, Aberdare and Merthyr Tydfil, but they have been reduced to an hourly service and terminate at Radyr, with a bus taking passengers to Cardiff Central.
The Merthyr to Cardiff route also have a second rail replacement bus between Pontypridd and Merthyr because of engineering works - doubling the usual travel time to about two hours.
First and last trains on Saturday
TRANSPORT FOR WALES
Merthyr to Cardiff
- First between Merthyr and Cardiff is 06:08
- First between Cardiff Central and Merthyr is 06:23
- Last between Merthyr and Cardiff is 20:43
- Last between Cardiff and Merthyr is 21:38
Aberdare to Cardiff
- First between Aberdare and Cardiff is 06:21
- First between Cardiff and Aberdare is 06:38
- Last between Aberdare and Cardiff is 21:21
- Last between Cardiff and Aberdare is 20:38
Treherbert to Cardiff
- First between Treherbert and Cardiff is 05:40
- First between Cardiff and Treherbert is 06:02
- Last between Treherbert and Cardiff is 20:46
- Last between Cardiff Central and Treherbert is 21:02
South Wales to London
- First between Cardiff Central and London Paddington is 07:49
- First between London Paddington and Cardiff Central is 08:14
- Last between Cardiff Central and London Paddington is 15:54
- Last between London Paddington and Cardiff Central 16:27
South Wales to Bristol/Bath
- First between Cardiff Central and Westbury is 08:25
- First between Westbury and Cardiff Central is 07:55
- Last between Cardiff Central and Westbury is 16:24
- Last between Westbury and Cardiff Central is 16:02
The reason why some valley line services can run, but start earlier in the morning and later in the evening on strike days, is because TfW does not just run the trains but owns the track and signal operations above Radyr after it was handed over by Network Rail two years ago.
Valley line routes to Rhymney, Coryton and Cardiff Bay and Cardiff's City Line are suspended as signalling for those lines is operated by Network Rail.
TfW services connecting Aberystwyth with the Midlands and linking Cardiff with Manchester and north Wales and Manchester are also not running - so racegoers attending Saturday's meeting at Chester have been warned there are no services running to and from the city.
Services between north Wales and London are suspended on strike days as Avanti West Coast will only run reduced services between Euston and Manchester, Liverpool, Birmingham, Preston and Glasgow.
CrossCountry trains between south Wales and Birmingham, and Nottingham and Bristol have also been suspended.
Please remember services are severely disrupted this week and we advise only travelling if absolutely necessary on strike days. On our site you'll find everything you need to know, including information on refunds, reduced timetables and travel advice 👉 https://t.co/X0ehMIRi0X pic.twitter.com/NQfiHRIfxW— Avanti West Coast (@AvantiWestCoast) June 20, 2022
TfW has warned passengers that services that are running are expected to be "very busy" while GWR said people faced "severe disruption" and asked them "to only travel by rail if absolutely necessary."
Across the UK, four out of five trains will not run during the strikes, with 4,500 services operating compared to the usual 20,000. Rail workers, such as maintenance staff, signallers and operations teams, are in dispute.
How are the roads looking?
As well as Saturday's rail strikes, the M48 Severn Bridge is shut from Friday at 19:00 until Monday at 06:00 for essential maintenance work to start inspecting the bridge's suspension cables.
The strike and bridge closure means Angie Ruston has to leave for work more than two hours before she clocks on.
The 58-year-old, who works at an artificial intelligence project in Bristol, has to be at her nearest bus stop in Chepstow for just after 07:45 to get into work for 10:00.
"It's a nightmare, a perfect storm for me," she said.
"I'd have thought whoever runs the bridge would have known there is a rail strike on, anticipate the possible excess traffic and put the closure off.
"It seems stupid to do it at the same time as the rail strike, there's no forward thinking.
"My journey to work normally takes me less than 50 minutes, it'll take me two hours on Saturday. It's not ideal so while I'm working between 10am and 3pm, I'll be out the house between half seven and 5pm.
"But on Sunday it's worse because there will be no buses or trains that get me into work by 10:00 so unfortunately I'll be late."
The double disruptions are not just affecting people's work but family plans too as Ilsehar Hopcroft has cancelled a family get-together.
"I had families coming from Norfolk and mum was going to come from Cardiff, but we've had to put that off," said the 23-year-old mum-of-one from Chepstow.
"It's quite frustrating as Saturday was quite important because of distance and Covid lately, we don't see them very often. It is having a huge impact on people."
Chelsea Hopkins said it took her almost seven hours to get home from work on Wednesday evening after her commute was affected when a lorry fire closed the M4 Severn Bridge.
Now the marketing manager, who lives 10 miles from Chepstow on the Welsh side of the bridge, said she was doing more logistics planning to meet a colleague at her work in Bristol to travel together to an event in Coventry.
"The bridge closures always seem to be incredibly inconvenient at the height of tourist season, during commute times or on school holidays," said the 30-year-old.
"I certainly support the rail strikers and rail is usually my backup plan. The traffic network around the bridges is pretty fragile, like the lorry fire on the M4 on Wednesday which caused tailbacks.
"It'll be frustrating but it has to happen, perhaps we can all have a weekend at home enjoying the area we live in - apart from those working".
National Highways said it was "not anticipating a significant impact" from the M48 Severn Bridge closure - especially with M4 Severn Bridge remaining open - after data showed a 4% rise in traffic on the first day of the rail strike on Tuesday.
"We understand this work may cause some inconvenience and disruption, but we are making every effort to ensure the impact on drivers is kept to a minimum," said Chris Pope of National Highways.
"These pre-planned inspections are vital to allow us to understand the current condition of the suspension cables."
Roads in Wales and Scotland especially are expected to be busier as most railway lines in both nations are shut during the biggest rail walkout for more than 30 years.
The AA predicted a surge in traffic as train passengers switch to road transport with the worst affected roads likely to be main motorway arteries.
Why is the strike happening?
The RMT union has said members working for train companies have been subjected to "pay freezes, threats to jobs and attacks on their terms and conditions".
Network Rail plans to cut 2,500 maintenance jobs as it tries to make £2bn of savings over the next two years.
The RMT said the jobs were safety critical and cutting them will make accidents more likely, so 40,000 rail workers have walked out over three days this week
Network Rail said it would not consider any changes that would make the railways less safe and that modernisation was needed.
Are Welsh rail workers striking?
RMT members are striking and they include people working for Network Rail, which maintains the railways throughout Britain, including Wales.
However, TfW - now owned by the Welsh government - is not in dispute with the unions although it has warned of disruption because its trains use railways run by Network Rail.
Welsh Education Minister Jeremy Miles said the Labour Welsh government was "obviously pleased" staff at TfW were not striking.
"Clearly the strikes elsewhere will have a significant disruptive impact in Wales and we are asking the UK government to do everything to avoid that disruption," Mr Miles told BBC Politics Wales.
"When people are put in the position that the UK government have, people don't have many options. Nobody wants to see strikes, not even the unions, but the UK government needs to now step up."
But Conservative Member of the Senedd (MS) Tom Giffard said the unions were "stuck in the past" so it was "really unfortunate these strikes are going ahead."
"Network Rail and the [UK government's] Department for Transport had said that negotiations had barely started before the unions started balloting to strike... and the timing of this strike was just to maximise disruption as best it could," added the South Wales West MS.
Will I be able to get a refund?
The Rail Delivery Group, which represents train operators, said: "If we cannot provide a service for customers due to strike action then we will refund customers."
It has not decided whether customers worried about disruption could cancel trips in advance and get refunds.
The National Rail website suggests there may be options such as switching to a different operator or travelling on another date. But it said customers would not be compensated for things such as hotel stays.
Season ticket holders will be able to apply for a refund for the days affected.
- FIGHT FOR YOUR RIGHTS: X-Ray returns and they've got your back
- SPOTLIGHT ON THE NHS: Is Covid masking a bigger problem with our health service?