The drama happened on the westbound carriageway of the M62 at junction 29, near East Ardsley.
The picture was taken at around 4.30pm today by the Press Association’s head of IT services, Andy Godfrey, 42, who was a passenger in a passing car.
He said: “We were crawling by with traffic queuing as the inside two lanes were shut. It’s obviously somebody’s pride and joy that’s gone up in flames.
“The driver was talking to a police officer there. There was a police car - and a fire engine coming up behind ready to put out the flames.”
West Yorkshire Fire and Rescue Service said three fire engines went to the scene, from Rothwell, Hunslet and Normanton, and one hose reel was used to put out the blaze.
They had no information on the cause of the fire, except to say it was “not malicious”.