The white van caught fire on the northbound carriageway between Junction 44 at Tadcaster and Junction 45 at Boston Spa.
A video from the scene shows firefighters working to extinguish the fire, as traffic starts to build up approaching the incident.
There are no reported injuries.
West Yorkshire Police have closed the road as the surface is made safe to travel on and a diversion is in place.
Heavy traffic is building back to Junction 43 at Garforth and Micklefield, the junction with the M1, with traffic moving at an average 5mph approaching the scene.
Traffic is also slow southbound as traffic passes the scene of the fire.