A 14-year-old girl remains in a serious but stable condition at Starship Hospital after she was hit by a car in the Auckland suburb of Sandringham on Thursday morning.

It is understood the girl was on her way to school when she when hit by a vehicle at a traffic island on Taylors Rd , near the St Lukes Rd intersection, about 8am.

People at the scene said the teenager was unconscious and bleeding from head injuries. The windscreen of the small grey Peugeot hatchback car was smashed on the driver's side, a witness said.

A teacher from the girl's school and a nurse were among those to first arrive.

The driver of the car - a woman believed to be in her mid to late 20s - was inconsolable at the scene.

The driver may have been distracted when she hit the pedestrian but it was not clear how, police said afterwards.

The incident was a harsh reminder for drivers to pay complete attention to driving when they are behind the wheel, Balmoral police sergeant Jason Loye said.

A police investigation is continuing.