Police allegedly saw the boy driving a stolen Hiace van when they attempted to intercept the pair on the Western Freeway about 2.30pm after he had been involved in a home invasion in Ballarat earlier in the day.

But he allegedly failed to stop and smashed into a parked VicRoads truck at speed, writing off the van.

The boy’s passenger, a young Ballarat girl believed to be in her mid-teens, died at the scene.

In response, the police air wing was called in to find the boy, who had allegedly fled on foot across nearby paddocks in the moments after the collision.

Speaking at the scene of the crash, Assistant Commissioner Doug Fryer said the boy allegedly stole another car before heading back to Ballarat.

However, police tracked the boy down to a house on Willow Grove in Wendouree, arresting him about 6pm.

“Everyone has choices to make, we’ve had a young man who made a very deliberate decision not to pull over,” Mr Fryer said.

“(He was) driving in such an erratic manner that a young woman is now dead.

“How did this happen? From what I’ve been told, it’s happened because that young man made a decision not to pull over.”

Two occupants of the VicRoads truck were hospitalised following the collision.

Ballarat-bound traffic on the Western Freeway was diverted to Old Melbourne Road as more than a dozen police vehicles arrived at the crash scene.

Detectives from the Major Collision Investigation Unit have launched an investigation into the incident and it will be overseen by Professional Standards Command.