Uploaded October 2025 | Updated September 2026, 1 hour ago
As part of our plans to expand Heathrow by building a third runway, a small section of the M25 will be realigned under the new runway.
The new realigned section of the M25 will be built 130 metres west of the current motorway, as it operates as normal. The new section of the M25 and the tunnels and bridges required for a new runway are constructed ‘offline’ minimising impact on road users and the local community.
Then, in a series of carefully planned overnight closures, traffic will be switched from the old route to the new wider and safer section of the motorway, 100% privately financed by Heathrow.
Building a new runway over a motorway has been successfully delivered at other airports including Frankfurt and Charles de Gaulle, Paris.
Heathrow will continue to work closely with National Highways to finalise the details of its plans.
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Follow us on Twitter @HeathrowAirport: twitter.com/HeathrowAirport
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Like us on Facebook: facebook.com/HeathrowAirport
As part of our plans to expand Heathrow by building a third runway, a small section of the M25 will be realigned under the new runway.
The new realigned section of the M25 will be built 130 metres west of the current motorway, as it operates as normal. The new section of the M25 and the tunnels and bridges required for a new runway are constructed ‘offline’ minimising impact on road users and the local community.
Then, in a series of carefully planned overnight closures, traffic will be switched from the old route to the new wider and safer section of the motorway, 100% privately financed by Heathrow.
Building a new runway over a motorway has been successfully delivered at other airports including Frankfurt and Charles de Gaulle, Paris.
Heathrow will continue to work closely with National Highways to finalise the details of its plans.
Want to hear more?
Follow us on Twitter @HeathrowAirport: twitter.com/HeathrowAirport
Follow us on Instagram @Heathrow_Airport: instagram.com/heathrow_airport
Like us on Facebook: facebook.com/HeathrowAirport
