Motorists have been warned to expect lengthy delays after two lanes of the M62 were closed.
A collision close to junction 21 at Milnrow on the westbound carriageway, heading towards Manchester, is causing congestion.
Queues are already back towards junction 22 for Saddleworth.
National Highways says two of the three lanes have now been closed as traffic officers, emergency services and recovery are in attendance.
But it says to expect delays of at least 90 minutes on approach to the scene and is advising people to allow extra time for their journey.
Routes around the affected area are also expected to be busier until the incident is cleared.