Traffic is crawling on the M1 southbound between Northampton and Milton Keynes while emergency services deal with a burning Mercedes on Tuesday afternoon (September 7).
National Highways traffic sensors shows queues for around ten miles with delays of up to an hour back to the Junction 15.
Two lanes have been closed near to Newport Pagnell Services and the agency is advising drivers to avoid the area for the next couple of hours.
There are also queues on the northbound carriageway as drivers slow down past the scene.
A spokesman for Northamptonshire Fire & Rescue said: "A crew from Mereway were called to a Mercedes on fire in lane one of the motorway at 1.29pm .
"Firefighters have used breathing apparatus, one hose reel jet and an ultra-high-pressure lance to put out the fire."