The motorway network near Preston has ground to a halt on Monday evening following a major crash to the south of the city.
Highways England had shut the M6 northbound at Junction 29.
It followed an overturned lorry blocking all lanes of the motorway.
Recovery vehicles are on scene following the incident which took place shortly before 3pm on Monday (9 October).
Two lanes of the motorway were reopened shortly after 6.30pm, with one lane remaining closed off by emergency services. The third lane was reopened shortly before 8pm.
A diversion was set up onto the M6 slip road, through the M65 roundabout, and then back onto the M6 northbound.
Drivers were experiencing delays of up to an hour and a half approaching Preston with traffic back to Junction 27.
Read more: Three new major roads approved for the west of Preston
An earlier breakdown on the M65 westbound at the M6 junction led to severe congestion on the approach to Preston as well as on the M6 southbound near Junction 29.
Lancashire Fire and Rescue Service had to rescue two people from the overturned lorry.
Two people were taken to Royal Preston Hospital to be checked over, the extent of their injuries is not known at this stage.