There will be disruption to rail travel over five weekends due to major work to upgrade a station on the East Coast mainline.
Passengers are being urged to check before they travel as work takes place at Durham station.
The £6m project will see 100 metres of track replaced and ten points - the equipment that allows trains to move from one section of track to another - renewed.
The work will also see upgrades to signalling equipment and improvements to the platforms.
Network Rail said that it is hoped that the upgrades will boost reliability and reduce disruption.
As work takes place, there will be major changes to services on:
Saturday 14 and Sunday 15 JanuarySaturday 21 and Sunday 22 JanuarySaturday 28 and Sunday 29 JanuarySaturday 4 and Sunday 5 FebruarySaturday 11 and Sunday 12 February
On these dates, trains will terminate at York or Newcastle, and some rail replacement services will be available.
LNER plan to run one train per hour between York and Newcastle using a diversion which will add around an hour to the journey time.
Passengers planning on travelling to, from or through Durham, Northallerton, Darlington and Chester-Le-Street are advised to plan ahead and allow extra time for their journey.
People are also being advised to check their journey before setting off via National Rail or the relevant train operator’s website.
Paul Rutter, route director for Network Rail’s East Coast route, said: “The work we’re doing in and around Durham in January and February will help boost reliability and provide smoother journeys for passengers.
A statement on behalf of train operators on the East Coast route: “We’re asking people to check before they travel to, from or through Durham station while important upgrade work takes place.
“We’ll be providing rail replacement services wherever we can to keep passengers moving, so our best advice is to plan ahead and allow extra time to compete your journey.”
Ben Simkin, regional director for the North East and Scotland at CrossCountry said: “We appreciate our customers’ patience while this important engineering works takes place.
"The works will improve reliability for customers travelling through the region. In the meantime, there will be replacement buses between York and Newcastle on these weekends and we ask that customers check the website and allow extra time for their journeys."
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