The A19 southbound is closed - queueing traffic due to an overturned car between the A1046 Haverton Hill Road (Portrack Interchange) and the A1130 Levick Crescent.
The car was travelling on the northbound carriageway when it flipped over onto the southbound carriageway.
The road is expected to remain closed for several hours. Police have extended the closure back to the Portrack Interchange.
Diversion is via the A66.