Christmas: Drivers reminded of Wales 20mph default limit
Drivers heading to Wales over the festive period have been reminded that the default speed limit in residential areas has been lowered to 20mph.
Traffic experts have warned roads will be congested for the three days before Christmas with the RAC predicting Friday will be the busiest of all.
Wales became the first UK nation to reduce limits in built-up areas from 30mph to 20mph on 17 September.
Motorists travelling to Wales for the first time since have been reminded.
"The 20mph speed limit could put a third onto your journey time," Wayne Short of The AA told BBC Radio Wales.
"So add more time if you need to be somewhere at a particular time. Just keep an eye on the signs as things have changed."
Analysts have forecast 21 million trips expected before 25 December and reckon roads will be 20% busier than last year - and the Christmas getaway has already been hit by strikes, storms and congestion.
Traffic data firm Inrix predicts the M25, M1, M6 and M4 will be the most congested motorways and passengers that plan to use main London rail stations Paddington, Victoria and Kings Cross may be hit by disruptions over Christmas.
Travel could also be affected by one of the six weather warnings in place across the UK between now and Christmas Day - including a yellow rain warning across west and north Wales between 22:00 BST on Saturday night and 18:00 on Christmas Eve.
Where will be busy on roads this Christmas?
Motoring experts have warned the worst traffic tailbacks on the UK's motorway network will be on the M25 around London - particularly on the stretch between the M3 and M40 near Heathrow Airport - and on the M1 between Luton and Northampton.
Drivers have also been advised the M5 around Bristol, the M60 around Manchester, the M6 between Lancashire and Birmingham and the M4 in south Wales and around Bristol to London will be among the busiest routes this Christmas.
"While Friday 22 December and Saturday 23 December look set to be the busiest travelling days, the unsettled weather forecast could lead to additional delays," said AA president Edmund King.
Inrix predict roads will be busiest between 12:00 GMT and 14:00 for the Christmas getaway so motorists are urged to avoid lunchtime journeys and either travel before 11:00 or after 18:00 on Friday or Saturday.
"On average, drivers could see travel times up to 20% longer this holiday season," said Inrix traffic analyst Bob Pishue.
"Travellers around Greater London could experience more than double typical drive times. Our recommendation is to avoid peak commuting hours and use traffic apps to minimise holiday travel traffic frustrations."
Most roadworks on England and Wales' main arterial routes will be paused over the festive period, including the 27 miles of roadworks on the M4 near Newbury, Berkshire.
Both Highways England and Traffic Wales has said some contraflows may remain at major roadwork sites for safety reasons and added repair works could also take place in the case of a emergency.
How engineering works will impact trains
Trains between south wales and London, Manchester and England's south coast will be affected by engineering works over the festive period as rail passengers have been warned to plan ahead.
London Paddington, the UK's second busiest station, will be shut because of construction work between Christmas Eve and Wednesday, 27 December so all mainline Great Western Railway (GWR) services to and from south Wales will start and terminate at Reading.
Passengers needing to travel on the affected dates are advised to use local trains between Reading and Ealing Broadway and London Underground Services.
Paddington is one of four major London railway stations that will be affected by station or line closures for a time over the festive period and passengers using Kings Cross, Victoria and Heathrow Airport could be impacted.
On Christmas Eve, the 07:55 GWR Swansea to Reading service will start from Cardiff Central and a rail replacement bus will run between Swansea and the intermediate stations to Cardiff.
GWR services between south Wales and Southampton will be affected between Christmas Eve and Friday 29 December as rail replacement work will close Southampton Central station.
Passengers for Southampton are advised to get off the train at Eastleigh and use a replacement bus service to Southampton. GWR have said journeys between south Wales and Portsmouth should be unaffected.
Trains between south Wales and Plymouth and Penzance will be affected by a signal upgrade on the line in Devon and Cornwall on Wednesday 27 December.
Passengers travelling between south Wales and Manchester on 27 and 28 December will be impacted by a line closure between Crewe and Shrewsbury so services will diverted via Chester, extending journey times.
There be no direct Avanti West Coast trains between north Wales and London Euston on 30 and 31 December and 1 January due to engineering work as services from Holyhead will terminate at Crewe.
The last direct train from Holyhead to London Euston on Christmas Eve is at 09:38 while the last direct train from Euston to Holyhead on 24 December is the 13:02 service.
The Severn Tunnel will be shut on New Year's Eve until 14:30 for work on overhead line equipment so buses will replace trains between south Wales and Bristol while long-distance services between Swansea and London will take longer and not stop in Bristol.
Transport for Wales have also warned some passengers may face disruption on services serving Cardiff, Chepstow, Gloucester and Ebbw Vale between Christmas and the new year.
As usual, no trains will operate on Christmas Day or Boxing Day and as Christmas Eve and New Year's Eve are Sundays, services may stop running earlier than usual on most routes so passengers are urged to check before travelling.
Eurostar and LeShuttle trains between the UK and France were hit by a "last minute strike" on Thursday, but this is now over and there is a progressive return to services.
When do the buses run over Christmas?
Most services on Wales' TrawsCymru inter-city bus network will operate a Sunday service with an early finish on both Christmas Eve and New Year's Eve - but some will not run at all on those days.
All journeys will be finished by 20:00 on 24 and 31 December with the 19:07 T4 bus from Cardiff to Merthyr Tydfil the final service on both days.
There will be no public transport in Wales on Christmas Day and New Year's Day while there will be a special timetable on certain routes in south-east Wales on Boxing Day.
The only public transport operating on every day throughout the festive period - including Christmas Day and New Year's Day - are the inter-city services operated by Megabus and National Express but in Wales, they will only serve destinations in the south.
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