A new Tube map has been released to mark one year until the Elizabeth line is launched.
The inclusion of the purple line is one of the most significant updates to the map in decades.
In December 2018 the line will operate in three sections from Heathrow Airport in the west to Abbey Wood and Shenfield in the east.
This will involve 15 trains per hour running through new tunnels built under the capital in the £14.8 billion Crossrail project, funded by the Department for Transport and Transport for London (TfL).
Direct services will operate from Reading and Heathrow Airport to Abbey Wood and Shenfield when the line fully opens in December 2019.
The line will serve 200 million passengers each year and boost rail capacity in the centre of the city by 10%, according to TfL.
London mayor Sadiq Khan said: "It's truly exciting that in only a year London will see the opening of one of the biggest new transport projects in a generation.
"The new map being unveiled shows how the first phase of the Elizabeth line will connect to key parts of the transport network in the heart of central London, substantially reducing congestion on other key Tube lines as London's population grows."
Elizabeth line trains will feature walk-through and air-conditioned carriages with live transport information and free wi-fi.
All 41 stations will be step-free from street to platform.
Rail minister Paul Maynard said: "Seeing the Elizabeth line on the Tube map for the very first time is exciting confirmation that we are closer than ever to delivering a transformative change in London's rail network.
"That means better, faster journeys for over half a million passengers per day, as well as offering new connections that will link people to Heathrow, Gatwick and Luton."
London transport commissioner Mike Brown added: "Our customers will soon benefit from the most significant increase in central London's public transport capacity for decades."