A man walking along the A27 near Chichester caused the road to be partially closed by police.
At around 7pm on Saturday, the left-hand lane of the westbound carriageway, north of Bosham, was closed with two police cars at the scene.
Officers were seen gathered under a bridge across the A-road by a reporter driving past.
Now, Sussex Police has explained what happened.
A spokesman for the force said: "A man was seen walking west along the side of the A27 west of Chichester on Saturday evening (10 November), he was taken to safety and later went on his way, away from the A27."