Due to a safety inspection of the track, trains have been forced to run at reduced speed on some lines.
The warning has been put out by West Midlands Railway, which says that disruption is expected until the end of Monday.
A post on its website says: "Due to a safety inspection of the track between Wolverhampton and Shrewsbury trains have to run at reduced speed on some lines.
"Train services running through these stations may be delayed. Disruption is expected until the end of today.
"We expect some of our trains to be affected by this incident.
"To see how this might affect you, please use the live departures & arrivals or plan your journey using the National Rail Enquiries real-time journey planner."