The M6 and M55 near Preston were gridlocked due to a medical emergency.
Police had closed the motorway at Junction 31 southbound.
A motorcyclist had become ill at the wheel and sustained serious injuries, according to police.
The motorway was closed shortly before 5pm on Sunday (19 November).
It is expected to reopen around 6pm.
Tailbacks are reported to junction 36 of the M6 and junction 3 of the M55 heading eastbound.
Delays were expected for Sunday drivers through until 8.30pm.