Three people are to receive hospital treatment after a collision close to a junction of the A19 this evening.
Northumbria Police said is dealing with the crash on the northbound carriageway at the junction with the A1231 Wessington Way and Sunderland Highway.
The North East Ambulance Service has said it is treating three patients from the one vehicle.
They are reported to have sustained spinal and head injuries and it is thought they will be taken to Sunderland Royal.
The service has a urgent response crew, a double-crewed ambulance, two hazardous response teams and a rapid response car on the scene.
The incident was reported to its call handlers by one of the crew, who were already on the road.
It was initially said to have involved four vehicles before it was established just one car had crashed.
The collision was reported to the emergency services at around 5.10pm, with traffic backed up to the A183 Chester Road.
Traffic is being diverted back down the A1231.
A spokesman for the force said: "Delays are expected in the area.
"Please avoid wherever possible."