A key section of the £50 billion HS2 high-speed rail line will be in a tunnel, the Government has confirmed.
Part of the line in west London will run in a tunnel under Ealing and Northolt, with HS2 saying this will shave 15 months off the build timetable and considerably reduce disruption to residents and traffic.
Confirming the tunnel decision, transport minister Robert Goodwill said: "We do not expect that many properties within the newly safeguarded area will be required for construction of the railway because the route will be in tunnel.
"However, some land on the surface is affected, particularly for construction purposes, and owners of this land may be able to take advantage of the statutory blight provisions."
The section given the green light today is a 5.6-mile tunnel section which will run between the interchange station at Old Oak Common and Northolt.
This new tunnel will link to an already-planned tunnelled section of the route running to and from West Ruislip in west London.
This will make an 8.75-mile tunnel in total - the longest on the whole 140-mile first phase of the line between London and the West Midlands, which is due to be completed by 2026.
A spokesman for HS2 Ltd said: "A tunnel is the best solution for this part of the route.
"By running our trains through a tunnel here we will save time during construction and there will be less disruption to residents, businesses and on local roads, particularly at Hanger Lane (on the A40 in west London).
"Our station at Old Oak Common will be a major transport hub allowing passengers to switch between HS2 and the Crossrail connections to Heathrow and the Great Western Main Line."
Mr Goodwill also confirmed that another tunnel section of the line would be constructed.
This would take the line into Birmingham using a new tunnel running under the M6 viaduct at Bromford.
HS2 said this would save school playing fields, public open space and community facilities, including Firs and Bromford Community Centre.