Cayson-Lei Walters was first time windscreen washer when he died at intersection

The Papakura teen always had time for cousins and little sister Kerrinlei (pictured). Photo / supplied

The father of a teenage boy hit by a car when washing windscreens said it was the only time his son had worked at the intersection.

Cayson-Lei Walters, 16, was struck on November 27 as he jogged across a busy intersection in Greenlane, Auckland.

He was critically injured and died in hospital a week later.

Cayson-Lei Walters as a boy with his dad Sando Walters. Photo / supplied

Heartbroken dad Sando Walters said his son, who had "an infectious and beautiful smile", had just finished a tech course that day and was hanging out with friends.

"He had never been window washing before," Walters told the Herald on Sunday.

"I think he had gone with some friends. It came as a big surprise to us that he was out there washing windows."

It is understood Cayson-Lei, known as Cayson, was crossing the road to see police officers speaking with his friend when he was struck and critically injured. Officers said he did not see the car.

On hearing his son had been hit and had serious head injuries, Walters gathered his family and rushed to Auckland Hospital "hoping for the best".

A tattoo done ten years ago on the forearm of Cayson's father Sando Walters. Photo / supplied

Specialists told the family there was little hope for Cayson, who was in a coma.

"He had surgery and then when I saw him in ICU I knew it was bad. I was in a state of shock actually.

"I had only ever seen a graze on him before, a scratch. His face was fractured, it was not something you want to see."

Walters said his firstborn child was a "free spirit" with a constant broad smile.

"As soon as he smiled he could take all of your pain away, it caught everyone off guard," Walters said.

The Papakura-raised boy was the oldest sibling and grandchild and was a "leader and role model" to many cousins.

"His cousins were his life, he surrounded himself with them and they looked up to him," Walters said.

"He had a confidence and when you have someone like that in your circle you gain confidence so his whole family are going to miss that."

Cayson's death is the second tragic death within the family.

The Greenlane intersection where Cayson-Lei Walters was struck by a car. Photo / Chris Loufte

Last year Walters' new partner had twin boys and one of them, Caius-Lei, passed away at three months.

"Cayson took Caius's passing really hard because he was so proud of his twin brothers," Walters said.

"For us losing Cayson so soon after his brother has brought a lot of misery, it has been really hard."

Walters said the thought of his son's future being cut short was painful.

The teen would have turned 17 next month and he and his dad had plans to travel around the South Island - they should have set out two days ago. "We were flying to Nelson and driving to Christchurch and up the coast, the tickets were booked," Walters said. "We had it all planned out into the New Year."

There had been unexpected proud moments that had lightened the past week though.

On the day of the accident Cayson had just completed final assessments for his course.

Last week Walters, along with Cayson's mother Hinemoa Herbert, attended their son's graduation ceremony and accepted a certificate in his honour.

"His tutors from the course came to the hospital and they came to his funeral and then they had a memorial graduation for him," Walters said.

"That was a nice moment."

After Cayson was critically injured, police issued a reminder of the dangers associated with traffic light window washing - which is now illegal.

Window washing became a traffic offence in September last year.

Those found unlawfully washing or offering to wash a vehicle on the road, which is not legally parked, could be fined $150.