London Bridge station will be partially closed throughout the evening rush-hour on Monday night, because of the Olympics.
Network Rail is expecting the station to have its busiest day ever, with an extra 70,000 passengers travelling through it to an Equestrian event at Greenwich Park.
In order to prevent overcrowding, platforms one to six will be exit only between the hours of 6pm and 10pm.
Passengers travelling with First Capital Connect (FCC) and Southeastern are advised to use alternative stations, such as Cannon Street, Charing Cross and Blackfriars.
FCC customer service director Keith Jipps said: "London Bridge is best avoided throughout the Olympics because it will be exceptionally busy, but on Monday evening our customers will not be able to get on to the platforms we use."