Strikes hitting Northern, Merseyrail and Southern routes
Train passengers across England are being hit by further action by striking union members.
Northern staff have walked out for three days until Monday, while Merseyrail staff are on strike and also plan action on 10 and 23 July.
Southern workers also plan to walk out on 10 July.
The RMT union is in dispute with the companies over driver-only-operated trains, which it says would be unsafe and lead to widespread job losses.
Mick Cash, RMT general secretary, said: "Once again RMT members are standing firm in the fight for safe and accessible rail services.
Sharon Keith, regional director at Northern, said: "We are doing everything we can to keep our customers on the move during the three days of industrial action affecting our network."
Northern said it expected to run more than 40% of its timetable and it would have additional rail replacement buses.
However, all services are expected to be extremely busy and travellers should allow extra time for travel, the company said.
On Saturday and Monday, most services are to run between 7:00 and 19:00 BST with many routes winding down from late afternoon. On Sunday most services will operate between 09:00 and 17:00.
Merseyrail trains are to run from 07:00 to 19:00 but some stations will be closed. There will be no trains running on Ellesmere Port, Hunts Cross and Kirkby lines.
Jan Chaudhry-van der Velde, managing director, said customers were urged to check before travelling.
He added: "The team has put together the best possible timetable that we can to provide a limited train service on both strike days."
The strike on the 23 July coincides with the final day of The Open golf championship at Royal Birkdale although the tournament's website says a Merseyrail service to get people to and from the venue is planned.
According to Southern the industrial action on 10 July is "not expected to have any further effect on services".
An ASLEF union driver overtime ban continues.