Engineering work across the rail network is expected to disrupt Christmas travel for passengers departing Oxford, with significant alterations scheduled at London Paddington and Birmingham New Street.
Network Rail will undertake a £152 million programme of nationwide infrastructure upgrades during the festive period.
Oxford passengers are among those likely to encounter changes to services on important routes.
London Paddington will close to trains from Christmas Day while engineering work takes place near Slough.
The programme includes replacing track, modernising overhead power equipment and delivering other improvements.
Most Great Western Railway services will remain unable to reach Paddington until January 4, although services will begin returning gradually from New Year’s Eve.
While Paddington is closed, selected GWR trains will finish their journeys at Reading, while others will be rerouted to London Euston.
Passengers are advised to confirm arrangements before departure and allow additional time for travel.
Changes will also affect journeys north of Oxford.
Birmingham New Street will not be served by trains from December 24 until December 28 as part of a three-year project to renew overhead line equipment at the station.
CrossCountry operates direct services linking Oxford and Birmingham, and its routes are expected to be affected.
Revised services and replacement transport will be provided during the closure.
Network Rail has stated that most of the national railway network will remain available over Christmas and New Year.
Journey-planning information has been updated to reflect the scheduled alterations.