The M61 motorway remains closed near Bolton as police respond to reports of a man on the wrong side of the bridge.
Greater Manchester Police were called to the incident during Friday rush-hour at around 5.30pm.
As of 9.30pm officers were still speaking to the man at the scene.
The motorway has been closed northbound and southbound between Junction 3 and 4 in the Farnworth area.
The closure has led to heavy queues and congestion in both directions.
Diversion routes are currently in place which are also heavily congested.
Some motorists have tweeted saying that they have been stuck in the traffic for over two hours.
One driver said: 'Set off from Stockport at 5.15pm. Just got home at 8.15pm. That's a 45 minute journey on a good day.
"Thank you for my Friday treat M61 and to Highways North West for getting us off the motorway."
North West Motorway Police tweeted: "Patrols have blocks on both North and Southbound M61 between junction 3 and 4 due to an incident. Delays likely whilst we deal."
At 6.15pm they added: On the M61, approximately 2 miles of queuing traffic in each direction approaching J3. Traffic has been temporarily halted while our Traffic Officers assist the emergency services with an incident."
It is believed that traffic is now being turned around and cleared off the motorway.
North West Motorway Police said they don't know how it will take for the issue to be fully resolved.
The incident is ongoing.
