An earlier lorry fire stopped traffic on the M1 near Hemel Hempstead and St Albans.
The incident began at around 2.41pm today (Wednesday, August 28), between M1 junction 8 (A414, Hemel Hempstead) and junction 6A (M25, St Albans), and involved a heavy goods vehicle (HGV).
Crews from Hertfordshire Fire and Rescue Service attended the blaze, which was on the highway's southbound carriageway.
Two fire engines from Hemel Hempstead as well as teams from Redbourn, Markyate, Garston and St Albans tackled the motorway fire.
Officers from Hertfordshire Constabulary were also called to the scene.
Motorists were advised to avoid the area, with delays of up to 60 minutes experienced due to diverted traffic in the St Albans area.
An oil spillage affected all four lanes.
Shortly after the incident began, a National Highways spokesperson said: "Traffic has now been stopped on the M1 southbound between J8-J6A, near #HemelHempstead due to the HGV fire.
"Please allow extra time for your journey."
A spokesperson for Hertfordshire Constabulary said: "We're currently assisting the fire service at the scene of a lorry fire on the M1 southbound, between junctions 7 for the A414 and 6a for the M25 interchange.
"Motorists are asked to please avoid the area at this time."
The fire was extinguished later the same evening, but the M1 remains shut overnight into Thursday, August 25 for emergency resurfacing works.
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