A 2-year-old boy was fighting for his life in the Starship hospital early today after he was hit by a car on a suburban Auckland road.

The boy - who was listed in a critical condition - was with two other children aged about 4 and 7 when the car hit him on Kepa Rd, Orakei, about 7.20pm. It was raining.

The driver, Richard Ram, had just driven through an empty pedestrian crossing. The children were crossing the road about 5m away.

The Herald understands the children were not accompanied by any adult. Mr Ram's sister Julia Haare, who owns the car, told the Herald at the scene that he was not speeding.

"He was driving only 50km/h. The kids would have appeared out of nowhere.

"He's a very responsible driver and nothing like this has ever happened to him before ... He was absolutely freaking out."

Ms Haare said her brother, a roofing contractor in his early 20s, lived in Remuera with their mother. His niece and two nephews live with them and Mr Ram helps to care for the children.

"Because he looks after those kids, he'll be absolutely horrified. This is the last thing he'll want to have happened."

Mr Ram was alone in the car when he hit the toddler and was on his way to visit a relative in the Orakei area.

Ms Haare rushed to Kepa Rd to comfort him, but he had already left with the police to be interviewed.

The serious crash unit is investigating the accident. Last night, officers were at the scene marking the road with small orange cones and speaking to witnesses.

The car Mr Ram was driving was stopped where it hit the child, near the Shell petrol station on Kepa Rd.

The officer in charge was still at the scene but he refused to comment.

The latest statistics from the Safekids injury prevention service show that on average eight child pedestrians under the age of 15 die every year in New Zealand.

Those aged in the 0-4 and 5-9 age groups account for the highest percentage of child pedestrian deaths.

Safekids is a service run by the Starship to help reduce the high rate of unintentional child injuries.

Director Ann Weaver said children were extremely vulnerable on and near roads.

"Children as pedestrians cannot anticipate the danger that's related to cars," she said last night.

"It's very hard for young children to realise that the cars probably can't see them because it's so dark.

"Also, they can't judge the distance of things like that. It makes child pedestrians very vulnerable."

Mrs Weaver said extra care was needed on the roads to prevent children being injured or killed.

"Caregivers need to ensure that they are with children who need to cross the road. Also, motorists need to be aware if they notice children on the road or near the road and be extra vigilant.

"It's about ensuring that you think about children of any age around cars and their ability to be able to make good decisions when they are on the road," Mrs Weaver said.

The Kepa Rd crash was the second serious road accident yesterday. A collision between a car and a truck in Otahuhu left a man in critical condition in Middlemore Hospital.