A woman was killed when a car and bus collided on the A1 Hillsborough Road just after the Moira Road junction.
Grandmother Muriel Wing (65), an auxiliary nurse at Craigavon Area Hospital, died when her silver Volkswagen Passat was in collision with a bus operated by Rooney International Coach Hire.
Both vehicles were travelling north yesterday morning and it is thought the car entered the A1 from the Moira Road junction acceleration lane.
Ms Wing was the lone occupant of the car. Three people who were travelling on the coach were treated by ambulance crew.
The tragedy brings the total number of road fatalities in Northern Ireland this year to 39, which is three less than in the same period last year.
Police closed the A1 in both directions for most of yesterday following the accident.
Traffic was diverted on to alternative routes, with the resulting congestion affecting the evening rush hour as people made their way home from work.
Rooney International is based in Hilltown, Co Down.
The company said in a statement: "Rooney International Coach Hire would like to express our sorrow about this morning's tragic events.
"Our sincere thoughts are with the family of the lady involved. We are also thinking of the driver and passengers of our coach. Thanks to everyone who have sent messages of support.
"We provide a regular commuter service between Newry and Belfast and the safe driving of our staff has always been paramount.
"Our thoughts are again with the family and friends of the deceased."
Police said the A1 was closed between the Hillsborough Road roundabout and Ballygowan Road/Dromore Road in both directions following the collision.
The PSNI's Rosie Leech said yesterday: "It is going to be a fairly substantial recovery, that there has been a bus involved, so that has complicated things.
"The issue has been further compounded by the fact that there are a lot of major roadworks schemes ongoing in the area and on some of the roads that we would otherwise think of using (for diversions)."
Local DUP councillor Allan Ewart said: "My thoughts and prayers are with the family of the person who died and also those injured in this horrific collision this morning on the A1."
Police investigating the collision appealed for witnesses. Officers would particularly like to hear from anyone who was travelling South bound on the A1 at around 8am and from drivers or pedestrians on the flyover bridge at Hillsborough who may have witnessed the collision. Anyone with information can call 101 quoting reference 234 05/08/16.
Meanwhile, a man in his early 30s from Belfast died following a traffic accident in Donegal on Thursday.
Gardai are investigating the crash between a car and a lorry on the main Letterkenny to Lifford Road.