In the first fatal crash, a car came off a sealed road near Lakes Entrance and smashed into a large tree, killing 18-year-old Darcey Kramme behind the wheel and her two friends.

They were front-seat passenger Josh Lavery, 17, and Lake Tyers Beach man Brett Harvey, 36, in the back.

A member of Swan Reach Football Club described Josh as a "very good footballer" and said Ms Kramme also supported the club.

Friends paid tribute to the young footballer on social media.

"Fly high Josh Laverty and the 2 others rest in peace," one friend posted on Facebook.

"I didn't just lose a great friend I lost a brother," another wrote.

A friend of Ms Kramme's posted: "If this is what heart-broken feels like then I don't want to feel like this anymore. Darcey Olivia, My best friend in the whole wide world was taken from us this morning."

A friend of hers since primary school wrote: "I'm struggling to find the right words to write, no words will ever be able to describe what I'm feeling right now ... your smile that lightened up the room, your contagious laugh that made me laugh every time, your sense of humour that used to have us both in stitches, your absolutely beautiful face."

Hours later, two people, believed to be a father and daughter, died on the Western Highway near Beaufort, west of Ballarat, in a head-on crash.

Victoria Police Assistant Commissioner Doug Fryer said the five deaths would have a terrible ripple effect as he pleaded with drivers to slow down and drive to the roads' conditions.

"Again, we see incredible trauma on our country roads," he said.

"It will affect the schools, it will affect the local sporting clubs, it will affect the local community."

He said the Lakes Entrance crash, which occurred about five kilometres from the Gippsland holiday town, will be particularly devastating for locals since the three people who died had grown up there.

"They went to primary school there, high school there, they were known personally to our local police.

"They've either had an error of judgement, but whatever it was, it's had fatal consequences to three young lives."

All three had been at a party prior to the crash on Colquhoun Road, near Mitchelson Court, around 2.15am on Saturday, he said.

Ms Kramme, a P-plater, was about to celebrate her birthday on Monday.

Her devastated relatives were almost too distraught to speak when parishioners at Bairnsdale's Seventh-day Adventist Church heard about her death on Saturday.

Police believe speed was a factor and are investigating if drugs and alcohol were also involved.

The second fatal crash, which claimed the lives of a 67-year-old man and 31-year-old woman from Beaufort, closed the Western Highway about 9.30am on Saturday.

/**/

It's believed the pair were in the car, which was towing a trailer with a ute on it, when it veered onto the wrong side of the highway, hitting a truck head-on, police said.

The five fatalities take Victoria's road toll to 224 deaths this year. There were 260 fatalities on the state's roads at the same time last year.

But Mr Fryer said regional fatalities were over-represented in the road toll with 113 of those deaths occurring on country roads.

"The death and injury in the country areas continues to rise," he said. "We know the country roads are far more dangerous than the metro roads."

The five deaths come as police continue searching for a motorcyclist driving on stolen number plates who ran down a female police officer about 4am on Saturday.

The rider appeared to speed up and hit the constable, throwing her into the air, after she indicated for the bike to stop at a breath-testing site on the Monash Freeway.

She broke her arm in the incident, police said.

The black 2013 Kawasaki Ninja 300 bore stolen registration plates, 1I4LM.

Anyone who witnessed the fatal crashes or has information about the motorcyclist can contact Crime Stoppers on 1800 333 000 or crimestoppersvic.com.au.