More than one in five Victorians who have died in road crashes this year were not wearing a seatbelt.

The state's road death toll is soaring and authorities are astonished at a "really dramatic increase" in people not bothering to wear seatbelts.

"That is quite extraordinary to me, as 50 years ago Victoria was the first place in the world to make seat belts mandatory," Roads Minister Jaala Pulford said on Monday.

So far this year, 218 people have died on Victoria's roads, which is more than the total road toll of 214 in 2018.

Of the 133 drivers and passengers killed so far this year, 27 were not wearing a seatbelt, Transport Accident Commission data shows. In addition, there were 40 deaths in which investigators have not yet been able to determine whether the victim buckled up.