The crash happened on the M62 westbound at J5 A5080 Roby Road (Huyton).
Dramatic pictures show vehicles turned over and huge queues forming, with emergency services on the scene.
There is congestion heading towards J6 and the main carriageway has been closed.
North West Motorway police tweeted: “Patrols are on scene with a multi vehicle RTC on the M62 WB between the exit & entry slip roads.
“All lanes are currently blocked so traffic is being diverted off at J5 to re-join the other side. Please consider alternative routes.”
This is a breaking news story and is constantly being updated.
Please refresh the page regularly to get the latest updates.
Reporters working on dailystar.co.uk will be working to source the latest information, reaction, pictures and video related to this story.
You can also follow us on Twitter @Daily_Star to get the latest news updates 24 hours a day.
Or download the Daily Star app for flash alerts on the biggest stories of the day.