The M6 has been closed near Preston after a collision involving a number of vehicles.
A closure is in place on the northbound carriageway between junction 32 for the Broughton Interchange and junction 33 for Galgate following the incident.
The incident involves an overturned HGV which has blocked all three lanes.
Lancashire Police were called to the incident at around 2.45pm.
A Lancashire Police spokesman said: "We are currently dealing with a serious collision on the M6.
"A HGV has overturned on the northbound carriageway between junctions 32 and 33 blocking three lanes.
"Motorists are advised to avoid the area and find alternate routes where possible."
Highways England has said that normal traffic conditions are expected between 5.30pm and 5.45pm.
There is also significant congestion on the southbound carriageway with delays of 30 minutes.
At 3.39pm, Highways England announced that lane one of three was reopened to traffic.