Police said the 76-year-old was driving south on the highway yesterday afternoon when her vehicle appeared to cross to the wrong side of the road and collided head on with a truck.

The Mollymook woman died at the scene, while the 30-year-old truck driver was not injured.

The highway was closed in both directions for several hours while police investigated the cause of the crash.

The woman was the third person to die on the South Coast highway in two weeks.

On November 6, an elderly woman was killed when the van she was a passenger in and a station wagon towing a box trailer collided at Gerringong.

One week later a motorcyclist died after he was knocked off his bike by a kangaroo on the Princes Hwy at South Nowra.

The 39-year-old man, from Bondi Junction, was riding his Harley-Davidson motorcycle south a kangaroo jumped onto the road.

The animal was hit by a car and bounced off into the man, knocking him from his motorcycle. He slid into the path of an oncoming Toyota Landcruiser.

Police have appealed for anyone who saw the Conjola crash to contact Shoalhaven Police via Crime Stoppers on 1800 333 000.