Baby hit as car veers off Sydney road

Three pedestrians, including a three-month-old baby and a teenage boy, have been hit by a car driven by an elderly man on Sydney's northern beaches.

The baby escaped injury and the woman and a 17-year-old boy are being treated for minor injuries in hospital.

The crash occurred in Collaroy on Tuesday afternoon when a sedan veered off the road.

The teen was treated at the scene before being taken to Royal North Shore hospital with non-life threatening injuries.

The 50-year-old woman suffered minor injuries and was flown to Royal North Shore with the three-month-old baby.

The driver of the car is believed to be in his 80s.