UPDATED: All lanes of M55 back open after earlier crash
Police were called to "two separate collisions at the end of the M55, at junction four for Blackpool," the North West Motorway Policing group said.
The Highways agency said traffic was "being diverted around the scene of the collision ... via the exit/entry sliproads," and said there were "delays and slow traffic" from junction three for Kirkham at around 1.50pm today.
The crash happened westbound towards the resort. No information on injuries was released, though firefighters and a medical helicopter from the North West Air Ambulance charity were called out.
"You can still get to Blackpool but there is heavy congestion in the area," Highways England added.
One motorist said there were tailbacks for "miles."
By 3.10pm, the crash had been cleared and all three lanes re-opened, police said. Delays were still being reported but were set to ease.