The A1(M) motorway in South Yorkshire has been closed after a lorry shed its load of paper and compressed card across the carriageway.
The road is closed northbound between junctions 35 and 36, on the outskirts of Doncaster.
Highways England, reported the accident shortly after 4am this morning, has advised motorists to expect delays.
It said at 7am that a clean-up operation was underway but the road remained closed.
Traffic is being diverted via the 'solid circle' diversion symbol.
From the M35, drivers are advised to take the third exit at the roundabout and join the M18 northbound.
They should then leave the M18 at junction three and take the first exit onto the A6182, continuing for approximately two miles to the junction with the M18.
After that, they are advised to take the first exit onto the A18, continuing for around 500 metres to the junction with the A630.
From here, they should turn left onto the A630, continuing for a further two miles before taking the third exit at the roundabout to rejoin the A1(M) northbound at junction 36.
Traffic is reportedly expected to return to normal at around 9.30am.