People travelled over the border into England for "non-essential" reasons during the first weekend of the second lockdown, rail bosses have said.
Transport for Wales (TfW) said it saw a rise in passengers going to places like Chester despite people being advised not to travel unless essential.
Wales is in lockdown from 23 October to 9 November with businesses shut, unlike places over the border.
TfW safety director Leyton Powell said the "majority of people are behaving".
"Certainly, over the weekend in areas like Chester, we've seen an increase in passenger numbers during the lockdown, an increase in what was expected," he told BBC Radio Wales Breakfast.
"We've got to recognise there are differences in the controls in pubs, clubs and restaurants opening across England.
"What we've had to do is put in additional queuing systems, to make sure all passengers are safe."
Wales is in lockdown but in Chester pubs, bars and restaurants, for example, are open, although they are restricted to table service only and must close at 22:00 GMT.
Mr Powell said rail timetables had been reduced "significantly" in line with Welsh Government restrictions to cut down on people travelling.
"We've taken out the majority of our journeys over the weekend that are for more social travelling, but we have kept in the services that we take people to hospitals or to work."
He called on people to "stay at home, save lives and only travel if your journey is essential".