A car is on fire on the M1 Credit: Jack Fenton
All lanes are now open following a car fire.
The M1 was blocked northbound between j4 and j5 for Watford.
Emergency services were called to the scene but Highways England have reported all lanes have opened.
Drivers reported that they were stuck for 30 minutes.
Long delays remain northbound and there are some queues southbound.
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