A key motorway has been shut down overnight with urgent emergency works required on the carriageway. The M1 has been sealed off to northbound traffic spanning from Junction 14 at Milton Keynes to Junction 15 following a major three-vehicle crash earlier on Tuesday, February 24.

National Highways confirmed its recovery team cleared all hazards, debris and bits of vehicle following the crash, except a "major spill" of diesel across three lanes of the carriageway. The spill has caused extensive damage to the asphalt, with contractors now working to ensure repairs will be carried out overnight, hopefully in time for the morning rush hour.

Emergency resurfacing is now underway and all traffic is being directed around the closure via a diversion, National Highways said delays remain low (at the time of writing).

No estimated reopening time has been provided.

"The duration of the repairs and surface curing cannot yet be confirmed, but it is expected that the road will remain closed throughout the night," a spokesperson for National Highways said.

The English highway body says advised road users should to follow signs mapping out the diversion route and should factor in extra time for their journey.

Road users are advised to follow the hollow diamond diversion symbol on road signs:

• Exit at J14 and turn left onto the A509 to the Northfield Road Roundabout.
• Take the third exit westbound onto the A509 Portway.
• Continue on the A509 Portway passing over the Pineham, Pagoda, North Overgate, North Skeldon, Belvedere, North
• Secklow, North Saxon, North Witan and North Grafton roundabouts (9 in total) to the A5/A509 Portway Roundabout.
• At the A5/A509 take the third exit onto the A5 northwest.
• Continue on the A5 to the A5/A508/A422 Old Stratford Roundabout.
• At Old Stratford Roundabout take the fourth exit onto the A508 northeast.
• Continue on the A508 through Grafton Regis and Roade to re-join the M1 at J15

National Highways said that delays are likely on approach to the closure and diversion routes.

"If this closure impacts on your planned route, please allow extra journey time. Plan ahead, you may wish to re-route or even delay your journey," National Highways said.

The M25 is also closed in both directions between Junction 27 for the M11 and Junction 28 near Brentwood to allow emergency works following a serious collision involving a lorry.

"The lorry left the carriageway and struck overhead power cables, causing significant infrastructure damage and a local power outage. Specialist engineers require full closures to safely rehang the cables across the motorway," National Highways said.