London Underground with a few stations to the south of River Thames. The only London Underground stations in Zones 7 to 9 are on the Metropolitan line beyond Moor Park, outside Greater London. Some stations are in two zones, and the cheapest fare applies. Paper tickets, the contactless Oyster cards, contactless debit or credit cards and Apple Pay and Android Pay smartphones and watches can be used for travel. Single and return tickets are available in either format, but Travelcards (season tickets) for longer than a day are available only on Oyster cards. TfL introduced the Oyster card in 2003; this is
Urban rail in the United Kingdom Line, via tunnels through central London, with a branch to . It is the largest construction project in Europe. Crossrail will start a full service in 2018, taking over suburban services operated by Abellio Greater Anglia to Shenfield, Heathrow Connect to Heathrow Airport and First Great Western to Reading. Once opened, Crossrail will be one of three partially underground suburban rail networks in the United Kingdom as the network cannot be classed as a Metro system like the London Underground or the Glasgow Subway. The Merseyrail and Glasgow commuter rail networks also have below ground stations. Crossrail 2 is a