A 'defect' in the road has forced Highways to close the M61 at Chorley this morning.
The closure applies to the southbound entry slip road at junction 8 (Chorley, A6).
Highways said the closure is due to a 'defect in the road surface' which requires emergency repairs.
It means traffic is unable to join the motorway in Chorley, forcing motorists to travel to junction 6 (Bolton North, Horwich) to join the M61.
People can also head north on the A6 to join the southbound M61 at junction 9 (Blackburn, Burnley, M65) at Walton Summit.
The closure is leading to severe congestion, with heavy traffic queuing along A674 Millennium Way and the A6.
Traffic officers are at the scene managing traffic.
Highways said congestion is expected to continue until around 8.45am, with an average delay of 10 minutes against expected traffic.
UPDATE: 9.36am - The works have now been completed and the southbound entry slip road at junction 8 has now re opened.