The Cardinia traffic management unit sergeant attended the terrible scene, where four teenagers had been killed in a collision between two cars in Hampton Park on June 28.

"With these sort of collisions, everyone is a participant," he said. "The individuals involved, emergency service personnel, government undertakers and even the media.

"It would take someone without a heart not to have been touched ... to see people there of such a young age."

Sergeant Atkins said he understood that the five survivors were expected to recover "although they are not going to be without [emotional] scars".

One was middle-aged while the rest were aged in their teens or early 20s.

Joel Brimble, 19, of Narre Warren South, died on his way to hospital. Although two of the four young passengers in the black Holden Commodore he was driving survived, Riyani Lowen and Anja Miler died at the scene.

An Frankston man, 18, died in the other vehicle, a Holden Statesman, while three others survived. Two of these, a Cranbourne man, 26, and a Seaford woman, 19, were seriously injured.

Sergeant Atkins said speed was a factor in the smash and alcohol, including a wine cask, was found at the scene.

"You could smell alcohol," he said. "But whether that was from drivers or occupants, at this stage, who knows until the toxicology results are in."

The accident veteran is frustrated that the state's death toll will keep rising until drivers modify their behaviour.

"People need to abide by road rules and signs," he said. "Until driver behaviour improves and people understand they can be injured or take someone else's life...all these deaths that are without meaning and preventable will keep happening. It's just a shame ... what do you do?"