Sydney toddler dies after being hit by car

A three-year-old boy has died in hospital after being struck by a car in Sydney's northwest while crossing the road with his mother.

The toddler was walking on the road with his mother in Eastwood on Wednesday afternoon when a car hit the boy, police said in a statement.

When ambulances arrived the boy was in a critical condition and was taken to Westmead Hospital, where he later died.

The boy's mother and the 71-year-old driver of the car were not injured in incident.

A witness told the Seven Network the boy and his mother had been crossing the road towards a park when he was struck.

His death was one of four on NSW roads on Wednesday

Two people died when their car crashed into a stationary truck north of Tamworth.

The female driver of the car and her male passenger - both believed to be aged in their 60s - died at the scene.

A pedestrian was fatally struck by a car in the Hunter Valley about 4.40am.

Police believe he may have been hitchhiking.

The man, who's yet to be identified, died at the scene south of Aberdeen.