The accident involved a green BMW 520i and a black Suzuki Baleno and happened between junctions 35 and 36 at around 7.15pm on 23 February.
Firefighters rescued two women, who were trapped in the Suzuki, by removing the doors and roof from the vehicle.
The women were taken to Royal Preston Hospital with what are thought to be serious but not life threatening injuries.
The motorway was completely closed for 1.5hrs while the rescue operation was underway.
Police have advised that lane closures are still in place this morning although traffic is being allowed to pass on the hard shoulder.