The stretch between Junction 38 and 39 near Doncaster is affected, with a diversion in place.
Highways England said the fire-damaged lorry, which was transporting vegetables, is in the process of being unloaded before recovery can take place.
There are long delays on the approach to the closure, with additional delays on the diversion route.
Traffic is diverted via the A638 northbound.
At North Elmsall roundabout, take the A6201 eastbound back to the A1 via Wrangbrook.