Trains between Sheffield and Leeds and York via Moorthorpe, near Pontefract, will be disrupted because of over-running engineering work.
Northern Rail has warned that services will be ‘severely disrupted’ until around midday.
The work has been carried out following the derailment of a freight train.,
A spokesman said: “Due to over-running engineering works, following the derailment of a freight train in the Moorthorpe area, all services between Leeds and York and Sheffield via Moorthorpe will be severely disrupted until approximately 12pm on Monday.
“An amended timetable will be in operation whilst work to reopen the track is completed.
“Train services between Sheffield and Leeds will be replaced with road transport between Wakefield Westgate and Swinton in both directions.
“Additional trains will run between Wakefield Westgate – Leeds, Thurnscoe – Sheffield and Fitzwilliam - Leeds.