Queen Elizabeth II unveiled the new roundel for the Crossrail, which will be named the Elizabeth Line and will appear in purple on the London tube map. The Crossrail, which is still under construction, will open in December 2018, with 200-metre-long trains which will run for more than 60 miles from Shenfield to Abbey Wood in the east to Heathrow and Reading in the west. It also includes a 13 mile underground stretch through London.

Accompanied by the Chairman of Crossrail, Terry Morgan and Mayor of London Boris Johnson, Queen Elizabeth II unveiled a sign with the purple "Elizabeth Line" logo when she visited the Bond Street Crossrail tunnel on 23 February.

The Queen, who celebrates her 90th birthday in April, became the first reigning monarch to travel on the London Underground when she opened the Victoria line in 1969. Government officials said it was a "fitting tribute" for her name to be added to the London rail line map.

Transport Secretary Patrick McLoughlin said: "Given Her Majesty the Queen's long association with UK transport, it is very fitting that this vital link across our capital will be named the Elizabeth line in her honour. This is an example of British engineering at its best and will transform the way people travel across London and beyond from 2018, bringing better and faster journeys, while boosting jobs and driving economic growth."

Elizabeth line
Queen Elizabeth holds a commemorative plaque given to her by Crossrail workers after she formally unveiled the new roundel for the Crossrail line Richard Pohle/ Getty Images
Elizabeth Line
Queen Elizabeth visits the new Crossrail Bond street station Richard Pohle/ Getty Images