Traffic was held on the M6 near Preston after concerns for a person on a motorway bridge.
Police closed the M6 near junction 29 at Bamber Bridge on Friday night while the situation was dealt with.
Motorists were urged to use the M65/M61 to avoid the area.
The motorway was reopened about an hour later.
Highways England thanked motorists for their patience.
Earlier, there was major traffic congestion in the Chorley and Horwich area after a two-car crash on the A6 at Blackrod.
Crews from Horwich, Bolton Central and Leigh went to the scene and cut a woman from a car.
The road was later reopened