A motorcyclist is in hospital after colliding with the central reservation on the A1.
Police closed the road in both directions while the man was treated by paramedics at the scene following the crash on Thursday evening.
A diversion was put in place between Carville and Chester-le-Street and drivers were urged to avoid the scene.
The extent of the motorcyclist's injuries are not yet known.
A spokesperson for Durham Constabulary confirmed that no other vehicles were involved.
A spokesman for the North East Ambulance Service said: "We were called just after 7pm to a road traffic collision on the A1.
“It appears that a motorbike has hit the central reservation.
“We have sent a double-crewed ambulance and a Hazardous Area Response Team."
He later added that the man had been taken to the University Hospital of North Durham A&E.
The southbound carriageway was reopened shortly before 8.30pm.
The northbound carriageway reopened just after 9.30pm.
