Nine dead on NSW roads in four days

Nine people have died on NSW roads in four days, prompting police to demand drivers "take responsibility for their actions".

Seven people died in six different crashes from Friday to Sunday, while two more died in separate incidents on Monday morning.

A 20-year-old man crashed into a barrier and rolled his car on the M1 near Wyong on the Central Coast just after midnight.

He got out of the wreckage but was struck by another car driven by a 20-year-old woman. The man died at the scene.

Then before 4am a ute hit a tree near Bundeena south of Sydney. The male driver died at the scene.

"Nine lives lost is more than a statistic, it means there are now nine families that will mourn a loved one forever," Assistant Commissioner Michael Corboy said in a statement on Monday.

"We need all road users to take responsibility for their actions in order to put a stop to more avoidable crashes."

A 72-year-old cyclist on Sunday morning was allegedly struck by a Holden Commodore driven by a teenage motorist on the NSW mid north coast, who then failed to stop.

He suffered non-life threatening injuries and was taken to Manning Base Hospital.

The 18-year-old driver was pulled over and arrested a short time later before being charged with failing to stop and causing bodily harm by misconduct.

Separately, a 45-year-old cyclist suffered head injuries when he was hit by a car driven by a 79-year-old man in Galston Gorge, NSW Police said in a statement on Monday.

He was subsequently flown to Royal North Shore Hospital in a stable condition.