The A19 was blocked and traffic was left queuing after a "multi-vehicle" collision.
The incident on the northbound carriageway was reported just after 1pm near to the sliproad leading to the A1018 to Ryhope and near to Seaton Lane at Seaham.
It and has caused a tailback towards Dalton Park.
The AA has reported the fire service and paramedics were sent to the scene.
The North East Ambulance Service said it sent two double crewed ambulances to the incident and took a man and woman to Sunderland Royal Hospital for further treatment.
It added the recovery of the vehicles involved is ongoing.
Highways England has since said one lane is now reopen and traffic is able to filter through.
It added: "Take care when passing the scene."