The M61 is now clear. It was closed between junctions eight near Chorley and nine at Walton Summit after a crash involving up to 10 vehicles.
The accident, which happened at around 6.10pm, had caused long tailbacks on the M61 and on the M65 as rush hour commuters sought alternative routes.
The traffic has been made worse by an incident on the M6, which had closed in both directions between junctions 26 at Orrell and 27 near Wrightington because of a man on a bridge.
Delays of between 20 minutes and half an hour had been reported up to Junction 30 of the M6.
North West Motorway Police said some traffic was illegally using the hard shoulder to get past on the M61.