A lane of the A19 near Hartlepool was closed after a car went onto its side.
One person was taken to hospital with injuries sustained in the incident, which took place at about 8.30am between the A179 and the A689 on the southbound section of the road.
Emergency services attended the scene before the lane was reopened.
A spokesman for Cleveland Police said: "We had a few reports at about 8.30am of a car leaving the road, which had gone onto its side.
"We attended along with the fire brigade and the vehicle was a black Volkswagen Scirocco.
"Police and the ambulance service were at the scene and the road was reopened at 9.50am."
A spokesman for North East Ambulance Service said: "We were called at just after 8.30am to an injured person involved in a road traffic collision near Elwick on the A19 southbound.
"We dispatched one rapid response, one ambulance and an officer.
"We took the patient to North Tees Hospital."