The M62 remains partially closed past junction 5, after a mini crashed into the central reservation and another vehicle.
Merseyside Police and the North West Ambulance Service were called just before 1pm after the crash by junction 5 westbound by the A5080 Roby Road in Huyton .
A spokeswoman for the force said one of the vehicles was obstructing lane three of the motorway .
The ambulance service said three patients received minor injuries and one has been taken to hospital for further treatment.
The motorway was initially closed in both directions causing severe tailbacks, and traffic was held at a standstill for a significant period while emergency services dealt with the incident.
The westbound carriageway is partially re-open, with some lanes on the eastbound side due to follow shortly.
The North West Motorway Police said in a tweet: "There will be lane 3 closures on both c/ways overnight for barrier repairs. Patrols anticipate delays could take up to 2 hours to clear fully."
It is understood that two of the three closed lanes were re-opened after 4pm.
North West Motorways Police said diversions remain in place utilising the slip roads as rush hour traffic builds.
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