OPO operation was introduced on the Northern line with the new trains. The last service with a guard operated on the London Underground in January 2000. On the Jubilee line a seventh car was added to trains in 2006. A new signalling system allowing automatic operation was commissioned in 2011. On the Victoria line, new trains were introduced between July 2009 and June 2011. A new signalling system has allowed 33 trains per hour from January 2013.
