London's long-delayed and over-budget Crossrail finally opens to passengers on Tuesday, offering faster journeys from Heathrow Airport and Berkshire in the west to Essex in the east through a series of new, long tunnels under Britain's capital.
The railway, which has been renamed the "Elizabeth" line in honour of Queen Elizabeth, is expected to carry 200 million people a year and will increase London's rail capacity by 10%, according to Transport for London (TfL).
