Greater Manchester Police received reports of a three-vehicle collision on the westbound carriageway between junctions 20 and 21 at around 10.10pm on Saturday 10 October.
Police said initial enquiries indicate that a Mercedes van collided with a Volvo, which then collided with a Vauxhall Insignia.
Officers attended alongside crews from North West Ambulance Service and Greater Manchester Fire and Rescue Service.
The man was arrested on suspicion of causing serious injury by dangerous driving and remains in custody for questioning.
The motorway was closed between the two junctions following the collision and has since reopened.
GMP’s Serious Collision Investigation Unit is continuing its enquiries. Officers want to hear from witnesses and anyone with dashcam footage from the area around the time of the collision.
Anyone with information can call 101 or use Live Chat at gmp.police.uk, quoting incident number 3374 of 10/10/26. The investigation unit can also be contacted directly on 0161 856 4741.
Information can be passed anonymously to Crimestoppers on 0800 555 111.
