London’s new Crossrail underground line is to open in autumn 2019 – nine months after its scheduled launch.
Transport for London (TfL) said more time is needed “to ensure a safe and reliable railway for customers from day one of passenger service”.
The project is running almost £600m over budget with extra funding required to complete the work, it was announced last month.
The route, to be known as the Elizabeth Line, had been due to open in December.
Crossrail, to be known as the Elizabeth Line, had been due to open in December
When fully operational, trains will run from Reading and Heathrow in the west through 13 miles of new tunnels to Shenfield and Abbey Wood in the east.
It will operate as three separate services – as previously planned.
Simon Wright, Crossrail chief executive, said: “The Elizabeth line is one of the most complex and challenging infrastructure projects ever undertaken in the UK and is now in its final stages.
“We have made huge progress with the delivery of this incredible project but we need further time to complete the testing of the new railway.
“We are working around the clock with our supply chain and Transport for London to complete and commission the Elizabeth line.”
Elizabeth line trains are already operating between Shenfield and Liverpool Street, and between Paddington and Hayes & Harlington.