More than 16 million drivers are set to take to UK roads, with four million travelling on Good Friday and 4.5 million on Easter Sunday.
Arriva Trains says passengers in Wales will face delays if travelling to London due to engineering works.
Details of affected services can be found on Arriva Trains Wales website.
Motorists can check for planned works, delays or latest incidents on the Traffic Wales website.
A South Wales Police spokesman said: "Motorists are advised to take note of travel information and allow plenty of time for their journeys."
Motoring organisation the RAC said the millions travelling would make it "hectic" on UK roads this weekend.
A spokesman said: "The first spring bank holiday of the year traditionally heralds the start of busier weekends.
"This Easter is set to be a hectic one.
"We recommend considering starting a journey earlier in the day if the plan is to drive a long distance."
It is also expected to be a busy weekend at Cardiff Airport with more than 11,000 passengers expected to fly to and from the Welsh capital.
Topping the list of destinations from Cardiff is Amsterdam with Dublin, Tenerife and Malaga also popular as Easter getaways.

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Fairfax said on Wednesday it would cut 125 editorial jobs - a quarter of its newsroom - to absorb slumping revenues.
In response, staff will strike until after next week's federal budget, one of the year's biggest local news days.
Fairfax's outlets include the Sydney Morning Herald, Melbourne's The Age and the Australian Financial Review.
The latest cuts come in addition to restructuring and cuts in recent years.
The Sydney Morning Herald's chief political correspondent James Massola tweeted "On strike for a week", while his colleague Judith Ireland urged that "quality journalism needs actual journalists to do the job".
Like most media outlets around the globe, Fairfax is suffering from falling circulation of its print editions and declining advertising revenue.
The fresh staff cuts were announced along with plans to scale back the use of freelancers.
"While we will be looking across all parts of the newsroom, at the end of the redundancy program we expect there will be significantly fewer editorial management, video, presentation and section writer roles," the publisher is quoted as saying in an internal note.
Australia's Media Entertainment and Arts Alliance, which represents the country's journalists, strongly criticised the planned cuts at Fairfax as a "dumb move".
"This will only undermine and damage its mastheads further, alienating its audience and leaving the editorial staff that remain to work harder and harder to fill the gaps," chief executive Paul Murphy said.
Fairfax is the main rival to Rupert Murdoch's News Corp Australia, which is also suffering from falling revenues and also has announced plans to cut jobs.
Motorists and rail passengers in Wales are being advised to check for disruption before travelling this Easter weekend.
[NEXT_CONCEPT]
Two days after a German-Iranian teenager killed nine people and then shot himself dead at Munich's Olympia shopping centre, this is what we know from the information given by police and prosecution sources.
[NEXT_CONCEPT]
Journalists at Fairfax Media, one of Australia's largest publishers, have gone on strike for a week to protest against massive job cuts.