UPDATE: The damage from a fiery high-speed collision that left three people dead in Melbourne's west is so horrific that police were unable to identify two of the deceased, authorities say.
Palmers Rd in Point Cook, 23km west of Melbourne CBD, has been shut to traffic after the crash occurred just after 7.30pm on Christmas Eve.
A shocking image of the scene shows one car engulfed in flames, with the wreckage of the other vehicle lying upside-down on the road.
Two occupants in one car and one person in the second car died at the scene.
A witness on Palmers Rd, who did not wish to be named, said she was sitting at the bus stop when a black car sped past.
"They were going so fast, I only had a second to step back from the road, I was so taken by surprise," she said.
"Seconds later, I heard a crash. I thought the driver was doing a stunt manoeuvre at the time it happened. They came over on to the right side of the road."
Assistant Commissioner Doug Fryer said the driver and passenger of the black Audi could not be identified because of the horrific damage to the car.
"At excessive speed, it's lost control and it's had a head-on (collision) with a small Jazz heading the other way that's contained two women," he said.
"Two innocent people just trying to probably get home to wrap presents and they've never made it.
"The vehicle that was speeding … The impact was extreme when this occurred and that vehicle has been incinerated.
"We don't know exactly what sex they are."
Asst Comm Fryer said the road was a 70km/h zone.
"It is clear to everyone who has had a look at this scene that the speed was well in excess of 70km/h," he said.
"It's clear even to a layman. This was just a tragedy that didn't need to happen.
"The sort of speeds we're talking about to cause this devastation are just crazy."
Mr Fryer said the Audi was not known to police, with drug and alcohol tests to come.
Detours are expected to remain on Palmers Rd until early Christmas morning.
Another traveller in the second car was transported to hospital with critical injuries.
The Major Collision Investigation Unit will investigate the tragic incident and police will prepare a report for the coroner.
This year's road toll is now 251, compared to 282 this time last year.