Rail passengers are braced for days of disruption as an estimated 80,000 trains are axed because of strikes this week.
The post-Christmas return to work will be hit as members of the RMT union stage industrial action today, Wednesday, Friday and Saturday.
Aslef, which represents drivers, will strike on Thursday.
Road travel will also be hampered when National Highways’ members of the Public and Commercial Services union walkout today and Wednesday.
Workers are unhappy at below-inflation wage rises as inflation - currently running at 10.7% - hammers real incomes and fuels the cost-of-living crisis.
Rail industry chiefs pleaded with commuters to only travel if absolutely necessary, allow extra time and check when first and last trains will depart.
On RMT strike days, around half of the network will shut down and only about 20% of normal services running.
Trains which run will start later and finish much earlier than usual, with services typically running between 7.30am and 6.30pm.
The train drivers’ strike on Thursday will affect 15 operators and will result in even fewer services running, with some companies operating "very significantly reduced" timetables.
Daniel Mann, director of industry operations at the Rail Delivery Group, said: "No-one wants to see these strikes go ahead and we can only apologise to passengers and to the many businesses who will be hit by this unnecessary and damaging disruption.
"We would advise passengers to only travel if it is absolutely necessary during this period, allow extra time and check when their first and last train will depart."
Aslef general secretary Mick Whelan said the union was "in it for the long haul", adding: "We don't want to go on strike but the companies have pushed us into this place.
"They have not offered our members a penny, and these are people who have not had an increase since April 2019.
"That means they expect train drivers at these companies to take a real-terms pay cut - to work just as hard for considerably less - when (retail price index) inflation is running at north of 14%.
"The train companies say their hands have been tied by the Government, while the Government - which does not employ us - says it's up to the companies to negotiate with us.
"We are always happy to negotiate - we never refuse to sit down at the table and talk - but these companies have offered us nothing, and that is unacceptable."
RMT general secretary Mick Lynch has accused the Government of blocking a deal to end the long running dispute.
He insists he is willing to negotiate, but is calling for an offer on pay, jobs and conditions his members can vote on.
The RMT is campaigning against plans to close ticket offices, cut jobs and move the industry to widespread driver-only operation.
There will also be disruption on major roads when National Highways staff walkout today and Wednesday.
Labour blasted the Tories for failing to negotiate with union chiefs - claiming the stance would hammer the economy.
Shadow Chancellor Rachel Reeves said: "The fact that Tories are happier to see a massive hit to the economy and prolonged chaos and misery than sit in a room with ordinary working people and negotiate with their representatives is unforgivable.”
