There has been a single-vehicle road accident on the A1 southbound towards Banbridge and Newry.
The accident happened close to the Hillsborough roundabout, just north of Banbridge.
The incident happened shortly before 5pm and queues are developing as far back as Sprucefield.
Recovery vehicles are currently at the scene assisting but the road has not been closed.
Avoid the area if possible as long delays are expected.
This is the second crash on the A1 in as many days, with the road closed in both directions following a single vehicle road traffic collision yesterday afternoon.
The male driver of the car remains in hospital where his condition was described as serious.
ANTRIM/DOWN: There is a crash on the A1 Belfast/Dublin Rd southbound at Hillsborough R/A, with delays on approach. https://t.co/pdsEzJTRQr
— AA Roadwatch (@aaroadwatch) July 19, 2017