Victoria Police is pleading with the public to obey the road rules after one of their own was killed in a charity motorcycle ride in honour of officers killed in the line of duty.

Key points: Victor Kostiuk, 59, was killed in a collision with a car near Orbost, in eastern Victoria

Victor Kostiuk, 59, was killed in a collision with a car near Orbost, in eastern Victoria He was praised as a respected member of the force who worked in the domestic violence sector

He was praised as a respected member of the force who worked in the domestic violence sector Four people were killed and four others airlifted to hospital in a 24-hour period

Detective Senior Sergeant Victor Kostiuk, 59, was riding alongside his son, also a police officer, in the Wall to Wall charity ride from Melbourne to Canberra when he was killed.

A car driving in the opposite direction on the Princes Highway east of Orbost, in far eastern Victoria, veered onto the wrong side of the road and collided with Detective Senior Sergeant Kostiuk's motorcycle.

He and his son had been travelling about 10 minutes ahead of the main group of 300 riders.

Mr Kostiuk had been in the police force for 40 years, recently working in domestic violence. ( Supplied )

The driver of the other car sustained minor injuries and is speaking with police.

Victoria Police Acting Chief Commissioner Shane Patton started the ride in Melbourne on Friday and told them to go safely.

He went through the police academy with the dead officer's wife and said the family was in mourning.

"Clearly they're shattered," he said.

"Victor was a fantastic member of this organisation, a member for nearly 40 years.

"He was really chuffed just the other day to have been recently appointed back to the rank of detective senior sergeant, something he was particularly proud of.

"It's a tremendous loss for Victoria Police."

Four dead in 24-hour period

Over 300 riders took part in the charity ride. ( ABC News: James Oaten )

Detective Senior Sergeant Kostiuk was working as the officer in charge of the Family Violence unit at Frankston.

"He's been committed to, in the latter stages of his career, combatting family violence," Acting Chief Commissioner Patton said.

"[He's] become somewhat of an expert in that field and very well respected with the innovative things he was doing."

The other officers taking part in the charity ride were "sullen but determined" to complete the ride, Acting Chief Commissioner Patton said.

"So they're determined to do that. That was a choice they made [and one that] Victor's son contributed to," he said.

"And that's what they've done."

Victor Kostiuk's death was one of four in a 24-hour period on Victorian roads and prompted a warning from police to all road users.

"This isn't just about the Victoria Police force losing a member. This is about a tragic loss of life," Acting Commissioner Patton said.

"Four people died yesterday. Four others have been airlifted to hospital.

"We as a community need to make sure that we all focus when we're using the road on driving as safely and as sensibly as we can."