The M6 southbound near Lancaster could remain closed for up to 24 hours after two lorries collided.
Fire crews were dispatched to the scene this afternoon following reports of people trapped and an oil spillage.
The M6 was closed between junction 34 at Lancaster and junction 33 at Galgate shortly after 3pm. One of the vehicles involved in believed to be a concrete mixer.
Police said the road would have to be resurfaced.
Traffic was being diverted through Lancaster on the A683, onto the A6 and back on the M6 at Galgate, causing massive tailbacks and delays.
No further details have been released.