Commuters and rail users could face delays and reduced services as staff go on strike.
Services by Arriva Rail North, which trades as Northern, will be hit by the latest strike tomorrow and Monday.
The RMT Union announced the latest strike dates earlier this month, in a long-running industrial dispute over safety, staffing and plans for driver-only trains.
Northern customers will be able to use train tickets on Arriva Bus services, including Yorkshire Tiger routes.
The company expects more than 900 services to run on both strike days between 7am and 7pm, but final trains on some routes may finish earlier.
It warned: “Trains are expected to be extremely busy, journeys may take longer than normal and connections to other services may not be available.
“Northern is advising customers to consider whether their journey is necessary and to recheck services before travelling.”
In the Wakefield district, no Northern services or replacement buses will operate at all to and from Featherstone, Glasshoughton, Knottingley, Moorthorpe, Normanton, Streethouse or any of the three Pontefract stations.
Services in and out of Wakefield Kirkgate and Westgate are also likely to be affected.
Full details of revised timetables can be found on Northern’s website at northernrailway.co.uk/industrialaction.
Timetables are subject to change and services may be added or removed depending on availability.
The most up to date information can be found by visiting journeycheck.com/northern