The M62, one of the UK’s busiest roads, was closed in both directions on Tuesday morning after a pedestrian died shortly after midnight.
Greater Manchester Police said emergency services were called following a collision between a car and an adult man at 12.15am.
The pedestrian, whose identity has not been released, was pronounced dead at the scene.
A 25-year-old man, who remained at the scene, was arrested on suspicion of causing death by dangerous driving and taken into custody for further questioning.
Police closed the highway between Birchwood and Eccles – exits 11 and 12 – in both directions and said it would remain closed for most of the morning. Drivers have been asked to avoid the area if possible.
Diversions were in place, but the closure caused long delays and congestion on the M62 and surrounding roads. National Highways North-West said there had been delays of at least an hour eastbound on the highway. There were also delays of up to 45 minutes on the M6 southbound approaching junction 21A.
Traffic England said roads were not expected to be cleared until 2 p.m.
The incident has had a knock-on effect on public transport, with Greater Manchester’s new Bee Network transport system warning of congested roads around the M62. “As a result, bus services will be significantly delayed,” he added.