Abbey Wood railway station in the context of Liverpool Street railway station

The Elizabeth line is a railway line that runs across Greater London and nearby towns, operating similarly to the RER in Paris and the S-Bahn systems of German-speaking countries. It runs services on dedicated infrastructure in central London from the Great Western Main Line west of Paddington station to Abbey Wood and via Whitechapel to the Great Eastern Main Line near Stratford; along the Great Western Main Line to Reading and Heathrow Airport in the west; and along the Great Eastern Main Line to Shenfield in the east.

Under the project name of Crossrail, the system was approved in 2007, and construction began in 2009. Originally planned to open in 2018, the project was repeatedly delayed, including for several months as a result of the COVID-19 pandemic. The service is now named after Queen Elizabeth II, who officially opened the line on 17 May 2022 during her Platinum Jubilee year; passenger services started on 24 May 2022.

London Paddington is a main line and tube station complex on Praed Street, Paddington, London, which has been the main terminus for the Great Western Railway and successors since 1838. The main line station opened in 1854 and was designed by Isambard Kingdom Brunel. In the year ending March 2025, it was the third busiest station in Great Britain after London Liverpool Street and London Waterloo, with an estimated 69.9 million entries and exits.

Paddington is the London terminus of the Great Western Main Line; passenger services are primarily operated by Great Western Railway, which provides commuter and regional passenger services to west London and the Thames Valley region, as well as long-distance intercity services to South West England and South Wales. The station is the eastern terminus for Heathrow Express. Elizabeth line services run through Paddington westwards to Reading, Heathrow Terminal 5, and Heathrow Terminal 4, and eastwards to Abbey Wood and Shenfield. Situated in London fare zone 1, it has two separate London Underground stations: one for the Bakerloo, Circle and District lines; the other for the Circle and Hammersmith & City lines. It is one of 11 London stations managed directly by Network Rail.

Crossrail is a completed railway project centred on London. It provides a high-frequency hybrid commuter rail and rapid transit system, akin to the RER in Paris and the S-Bahn systems of German-speaking countries, known as the Elizabeth line, that crosses the capital from suburbs on the west to east and connects two major railway lines terminating in London: the Great Western Main Line and the Great Eastern Main Line. The project was approved in 2007, and construction began in 2009 on the central section and connections to existing lines that became part of the route, which has been named the Elizabeth line in honour of Queen Elizabeth II who opened the line on 17 May 2022 during her Platinum Jubilee. The central section of the line between Paddington and Abbey Wood opened on 24 May 2022, with 12 trains per hour running in each direction through the core section in Central London.

The main feature of the project was the construction of a new railway line that runs underground from Paddington Station to a junction near Whitechapel. There it splits into a branch to Stratford, where it joins the Great Eastern Main Line; and a branch to Abbey Wood in southeast London.