Last month, the Rail, Maritime and Transport (RMT) union announced fresh strike action across five train operators for 8 and 9 November - Wednesday and Thursday this week.
Spanning Southern, Greater Anglia, Merseyrail, Northern and South Western Railway, the walkouts are over a spreading row regarding the role of the guard, and so-called driver only operation.
Here's a roundup of what we know...
Which train operators are affected?
On Wednesday 8 November, workers on Southern, Greater Anglia and South Western Railways have been told to strike for 48 hours.
Northern and Merseyrail workers have been told to take action for 24 hours on Wednesday.
What's this all about?
The union is in dispute with rail firms over driver-only operated trains. The row, which the union says is over vital safety concerns, has been running for over a year on Southern rail, and has spread to other companies too.
South Western Railway, which will be caught up in the row for the first time, said its discussions with the union concerns the introduction of a new fleet of suburban trains. The train firm said as part of talks over how they'll be operated, it has guaranteed a guard on every train.
Hasn't that been going on for a while?
The RMT has been embroiled in a long-running row with Southern in particular. Earlier this month, Southern struck an initial deal with train drivers' union Aslef, which the union's members will vote on. But the RMT was not involved in talks and remains in dispute with the firm, though its action has caused less disruption as walkouts by its guards are less disruptive than Aslef's drivers.
We're set to find out tomorrow whether Aslef members accept that deal to bring their dispute to an end.
Any chance it'll be called off?
Talks have been held between the union and train firms, but the RMT said on Friday they had been unsuccessful, and the strikes remained on. There have been cases where action industrial has been called off last minute, but at the moment, the RMT has said the Wednesday and Thursday walkouts remain on.
What services will be running?
South Western Railway said it will run more than 60 per cent of services through both strike days in November, but has published a contingency timetable showing replacement buses on some routes.
For the peak services to London, SWR said it will run about 70 per cent of the normal number of seats, but has warned that services may well be busier than normal though. More details its contingency plans here.
(Click or tap to view full-sized version.)
SWR train service during November strikes:
Southern said it will be "business as usual" on most routes, with some alterations, including that some peak hour services between Ashford International, Rye and Hastings will not run. The full Thameslink service is expected to operate on all routes, and while Gatwick Express services won't be affected by walkouts, some trains have been removed for the leaf-fall period. It has compiled a full list of limited services, including Guildford and Marshlink ones.
Merseyrail said there will be "a reduced train service" on 8 November, with no trains running on the Ellesmere Port line during the action. Most services will run between the hours of 07:00 and 19:00, but there will be a break in service during the middle of the day, and some stations will be closed. Full timetable here.
Northern will operate a reduced service, and on strike days, the majority of available trains typically operate between 07:00 and 19:00, with many last trains leaving before 7pm. It typically operates between 40 and 50 per cent of its usual services. It has warned some stations will have no train service, while the trains that do run, and any replacement bus services, are usually very busy. It will update its site with more detailed travel information on timetables here.
Greater Anglia operated a normal timetable for the last industrial action this month, though this month it is dealing with planned Network Rail works, so has planned service alterations information due to that here.