The Taw Bridge in Barnstaple was shut in both directions earlier this afternoon (Monday).
It is understood the bridge closed at around 1.10pm and there was very slow traffic around the town.
A police spokesman said: “We were called just before 1pm with reports of a man on the wrong side of the railings.
“A closure was put into place as emergency services attended.
“The man soon returned to a place of safety and the road reopened at around 1.45pm.
“He is now being supported by mental health professionals and being taken to NDDH.”