London Underground has increased the number of trains running on the Piccadilly and Jubilee lines to meet increased demand.
Saturday services on the Piccadilly line are now almost as busy as weekday peaks, according to the rail operator, and a new timetable has been produced to meet capacity.
Services between midday and 5pm on Saturdays have been increased from 21 trains an hour to 24, while an extra three trains per hour have also been added to evening and weekday services.
Extra trains have also been made available on the Jubilee line, allowing extensions of the full peak service of 30 trains per hour during particularly busy periods.
London Underground says this will also mean more trains on weekdays during off-peak hours and on weekends.
The changes have been made as part of wider plans to cope with growing demand across the network.
Latest annual figures showed the underground carried 1.265 billion passengers in 2013-14, compared with 1.229 billion the previous year.