The middle section of the new Elizabeth Underground line, at a cost of 19 billion pounds, opened under Britain’s capital, London on Tuesday morning.

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 Londons rail capacity by 10%, according to Transport for London (TfL).

The opening will help cut journey times and boasts longer and more spacious trains, while the slew of new stations will improve transport connections in Southeast England. The line will run east to west, connecting central London, the West End, the financial districts, the Docklands and the commuter towns in Southeast England. Importantly, it will connect to Heathrow Airport.

Opening Elizabeth Line is set to be followed by other sections in the east and west by autumn, including stations at Heathrow and Reading, as well as in Essex and southeast London, an area that lacks underground stations.

The project was delayed, with construction eventually taking three and a half years longer than planned.