Over two weekends in February, the junction near Leuchars station will undergo work where Network Rail engineers will work around-the-clock to renew points and replace track.
The closures will take place over the weekends of Saturday February 19 to Sunday 20 and Saturday February 26 to Sunday 27.
Leuchars is the closest station to St Andrews and the junction is vital for connecting train passengers between Fife, Edinburgh and Dundee and Aberdeen. The work aims to improve the reliability of the track and means the junction won’t need to be renewed again for decades.
Due to the complexity of the engineering work, the project cannot be delivered without some short-term closures of the line.
Passengers are being urged to check their journey before travelling and more information on the changes to services over these weekends.
Liam Sumpter, Network Rail route director for Scotland, said: “The work we are doing is part of a five-year, £4bn investment in our railway.
“We understand the inconvenience this work will cause to some passengers but renewing such a complex piece of our railway cannot be accomplished without a short-term closure of the line.
“Our engineers have carefully planned this project to be completed as quickly as possible and we are working hard alongside our train operators to keep passengers informed of the changes to services during this important investment in the railway.”