But nothing is more difficult than seeing people die in “avoidable” crashes because they are not wearing a seatbelt, or wearing one incorrectly.

Three people were killed in fatal car crashes because they were not wearing a seatbelt last financial year, and another person was killed because they wore it incorrectly.

Tuesday marks the start of Tasmania Police’s Seatbelts Save Lives campaign – a new initiative aimed at preventing avoidable deaths on the road.

“It's these crashes which are survivable, where people are dying or receiving significant injuries - lifelong injuries - where you just think 'why did that have to happen?'” Sergeant Clark said.

But his almost 30 years with Tasmania Police, including five as a frontline crash investigator, have shown him that a seatbelt’s incorrect use can prove just as costly.

“Quite often, if people are travelling in cars, especially in the back, they'll slump down in the seat and twist around,” he said.

“The two crashes that stick in my mind, both weren't wearing their seatbelts correctly, both those people died because the seatbelt caused massive internal injuries across their spleen and their internal organs. Yet everyone else in the car, who were wearing their seatbelts correctly got out with relatively minor injuries.”

Out of the 29 people killed on Tasmanian roads last year, about 17 per cent were not wearing a seatbelt.

Seatbelts Save Lives will see police use public message boards, social media and traditional media to express the importance of correct seatbelt use.

People in vehicles are urged to adjust seatbelts to fit securely around their waist.

If the seatbelt is irritating, then a sheep skin seatbelt cover can reduce discomfort.

Seatbelts Save Lives will continue until the end of June 2017.