London Heathrow Airport fire: Has the M4 been closed? Stretch of motorway shut after substation fire

After a fire erupted a substation in Hayes late last night (March 20), power was knocked out from Heathrow Airport in London. The airport is closed today, with thousands of flights cancelled and only a handful diverted.

Transport options have been suspended to and from the airport, and now the nearby motorway has also been affected. It comes after National Express cancelled all services to Heathrow until at least midnight, with Ryanair offering “rescue flights” that have been dubbed as “profiteering” by critics.

According to National Highways, which manages the country’s motorway network, a section of the M4 has also now been closed.

In a statement posted on X, a spokesperson for the agency said: “The M4 spur for Heathrow Airport is closed southbound between the M4 and J4A due to the closure of Heathrow Airport today following a large fire at an electrical substation.”

At the time of publication, there has been no indication as to when this section of the motorway will be reopened. It’s not the only part of the M4 that is being closed, either.

Over the course of the weekend, a stretch of the M4 between junction 18 for Tomarton and junction 19 at Hambrook will also be closed for bridge repairs. This will come into effect from 7pm tonight (March 21) and remain in place until 6am on Monday, March 24.

“Avoid travel if possible, and expect delays,” National Highways advised. “This is one of the south-west's busiest sections of motorway. We expect the closure will cause substantial disruption.

“If possible, please avoid driving on the M4 round Bristol during the closure. If you have to travel, allow plenty of extra time for your journey using signed diversion routes.”