The M18 northbound was closed between the M1 and junction one, and the air ambulance had been to the scene.
National Highways said on social media: “Traffic has been released on the #M18 southbound, following the serious collision. The #M18 northbound remains closed between #M1 and J1. There is approx. 5 miles of congestion on approach to the closure.”
They said the air ambulance attended.
An update in the last few minutes reported it had re-opened, but with traffic jams still there.
They added: “The #M18 northbound is fully open between #M1 and J1 following the earlier collision.
“Please allow time for the delays to ease, approx. 3.5 miles of congestion remain in place.”
Delays have also been reported to be affecting bus services as a result if the motorway incident