Rail passengers are bracing for the first national timetable change since the chaotic introduction of new schedules in May.
Industry body the Rail Delivery Group (RDG) warned there may be "some impact on punctuality as the new timetable beds in" after its introduction on sunday.
Similar statements were made ahead of the summer timetable change, which is crippled large parts of the network in the north and south-east of England.
The RDG insists the industry is "learning lessons" from the disruption and has decided to reduce the scale of the alterations in the winter timetable.
Darren Shirley, chief executive of the Campaign for Better Transport, said: "It is not possible to lose weight again this winter.
"Passengers have already had a bad year and do not deserve to endure any further problems with their journey."
Following the May timetable launch, Govia Thameslink Railway (GTR) and Northern Canceled to 470 and 310 trains respectively each day.
Train companies, government-owned infrastructure company Rail and Transportation Secretary Chris Grayling have all been blamed for the chaos.
A review by Office of Rail and Road (ORR) chairman Professor Stephen Glaister called for the information to be provided to passengers.
Anthony Smith, chief executive of watchdog Transport Focus, said: "This time around passengers are looking forward to a smooth set of timetable improvements.
"Passengers paid a hefty price for the catalog of over-optimism, missed deadlines and blurred accountability that led to a buzz of timely crisis and ensuing chaos. To regain their trust, passengers need to see that lessons have been learned. "
Rail timetables are changed twice a year, in May and December.
The decision to scale back Sunday's change has been controversial as it wants to delay the launch of some new services.
South Western Railway said it was "disappointed" it is not going to go ahead with its planned "major timetable change" which would have led to extra services and more capacity.
Judith Blake, Leader of Leeds City Council, said: "Yet again, a major decision on rail services has been made without warning, without consultation with northern leaders and without a voice for passengers."
Among the improvements are 200 additional weekday services on Thameslink and Great Northern routes and a reduced journey time between Edinburgh Waverley and Glasgow Queen Street.
RDG regional director Robert Nisbet said: "We know people in some areas might be concerned about another timely change, but as the Glaister Review acknowledges – the rail industry has worked together to start learning the lessons from May.
"As with the introduction of any new timetable, there may be some pockets of disruption as people go to new journeys and train times, so we advise people to check before traveling next week."