UPDATE 3.03PM: All northbound lanes of the Hume Highway are open at Old Mandemar Rd after a car crash. Heavy traffic is slowly easing.
UPDATE 2.39PM: One lane of the Hume Highway has re-opened north bound.
A NSW Ambulance spokesperon said one of the female patients was transported to Westmead Hospital by chopper, one patient to Liverpool by chopper, one to Bowral by road and one to Liverpool by road.
EARLIER: Police and emergency services are on the scene of a single vehicle crash on the Hume Highway at Mittagong.
Just after 1.10pm on December 20 emergency services were called to a crash on the Hume Highway on ramp at Mittagong.
A NSW Ambulance spokesperson said the car had rolled at high speed.
There were four people in the car, three of whom are out of the car and walking on scene.
A NSW Ambulance helicopter is on scene attending to a female passenger with “serious leg injuries”.
Both northbound lanes of traffic are closed.
A witness reported that traffic is queued for about four kilometres.
Avoid the area if possible.