Passengers are reminded to check before travelling over the next three weekends (February 24-25, March 3-4 and March 10-11), as Network Rail undertakes major work to reduce delays and improve reliability on the Brighton Main Line.
Network Rail engineers will be working between Purley and Gatwick to replace track and sets of points and improve drainage.
The work is part of a £300m government-funded programme to tackle delay hotspots.
On Saturday February 24, Saturday March 3 and 10 a half-hourly Gatwick Express service will operate between London Victoria and Brighton, calling at Gatwick Airport. Other services will be significantly altered and bus replacement services will be in operation on some routes.
On Sunday February 25, Sunday 11 March 4 and 11 2018 buses replace all trains between Redhill and Gatwick Airport or, in some cases, Three Bridges.
There are no direct trains between London and Gatwick Airport or the Sussex coast, however there will be half hourly Thameslink trains between Brighton and Gatwick Airport. Other services will operate to a revised timetable.
A Network Rail spokesperson, said: “This work is part of major programme to improve performance on the most unreliable parts of the south east network.
“Passengers using the Brighton Main Line in particular have suffered from delays and deserve better. While this work and others planned for the year ahead will cause short term disruption, passengers will experience a better service when our work is complete. Please remember to check with your train operator before travelling.”
A spokesperson for Govia Thameslink Railway, which operates Southern, Thameslink and Gatwick Express, said: “There are some significant changes over the next three weekends for Network Rail to improve reliability on the Brighton Main Line, which is the most congested rail route in the UK.
“We urge passengers to check ahead using www.nationalrailenquiries.co.uk and to allow more time for their journeys.”
Also as part of the £300m programme, Network Rail will be carrying out a track upgrade in the Gatwick area over the May bank holiday weekend.
“Two major closures to upgrade the track and signalling and repair historic tunnels between Three Bridges and Brighton/Lewes are also planned for the October 2018 and February 2019 half-terms.”
To find out more visit www.brightonmainline.co.uk.