A woman, whose age has not been released, died after being hit by a semi-trailer about 4pm on Sunday.

She had pulled over to the side of the road and was hit by the B-Double truck after stepping out of her vehicle. The truck was travelling north towards Sydney and collided with the woman near the intersection of Hume Highway and Golden Vale Rd at Sutton Forrest.

Peter Frazer lost his daughter Sarah in a similar accident in February and has been campaigning for changes to rules around roadside hazards.

''The loss of this woman is yet another tragic reminder that when approaching a stationary vehicle, it is essential to slow down and if safe to do so, move over into an adjacent lane,'' he said.

Sarah Frazer, 23, and tow truck driver Geoff Clark, 40, were killed by a southbound truck on the highway south of Mittagong. Ms Frazer’s car had broken down and Mr Clark had stopped to help her.

Mr Frazer started a petition in March and collected more than 12,000 signatures, calling for breakdown lanes to be widened to at least 2.5 metres. Mr Frazer also started a group called Safer Australian Roads and Highways, in memory of his daughter. A coronial report is being prepared about the latest incident.

The truck driver involved in yesterday's collision was immediately breath tested and did not give a positive reading of alcohol, police say. After assisting police, he began receiving counselling provided by his employer. The accident also caused significant traffic delays in both directions of the Hume Highway.