On average at least 10 per cent of people killed on NSW roads each year are not wearing a seatbelt, which police say could have prevented their death.

Last year 30 people involved in fatal accidents on the state's roads were not wearing a seatbelt, Transport for NSW data shows.

This represents 13.1 per cent of vehicle occupant deaths, and it is the highest rate since 2016.

The trend is continuing this year with 19 of the 79 drivers and passengers killed on NSW roads not wearing a seatbelt or child restraint.

Of those 19 fatalities, 74 per cent of them (14 people) were killed on country roads.

Country roads also account for 75 per cent of all road deaths in NSW (59 out of 79).

Inspector Macfarlane, also the NSW Police western region traffic tactician, has attended many roadside fatalities and the outcome for those not wearing a seatbelt if often horrific.

"It's very obvious to police if the occupant hasn't been wearing a seatbelt," he said.

Inspector Macfarlane said when your car suddenly stops during a crash, your body will keep moving forward.

"Without that restraint the body hits panelling, the steering wheel and other hard surfaces," he said.

"We see people getting ejected, loss of limbs and what might have resulted in minor injury ends up with major injuries or a fatality.

"It beggars belief why you would increase your risk of death or injury by not wearing a seatbelt."

Inspector Macfarlane said fatalities when a vehicle occupant wasn't wearing a seatbelt often happen when the driver was "just going around the block or just up the paddock".

"It's a real cultural thing," he said.

"It shouldn't be about whether the police are going to fine you, it's a safety thing."

Transport for NSW deputy secretary for safety, environment and regulation Tara McCarthy said the fatality rate on country roads is four times that of metropolitan roads.

"The rate of serious road-related injury among residents in rural areas is nearly twice that of those in major cities [and] not wearing a seatbelt increases the risk of serious injury or fatalities in a crash," she said.

"Drivers killed while not wearing seatbelt are often associated with other risk taking behaviours such as speeding, drink driving and drug driving.

"These other dangerous behaviours increase the likelihood of the crash occurring and not wearing a seatbelt increases the severity of the trauma outcome for the driver."

As part of the Rural and Regional Seatbelt Program all school buses in regional NSW will have seatbelts by the end of 2021.

Under the program, 861 new school buses with seatbelts have been delivered to regional areas and 273 buses have had seatbelts retrofitted.

During the 2018/19 financial year, 20,937 penalty notices were issued for seatbelt offences, Revenue NSW data shows.

The penalty for drivers not wearing a seatbelt is $344 and three demerit points, six in double demerit periods.

Drivers are also responsible for ensuring each passenger is wearing a properly secured and adjusted seatbelt or is in an approved child car seat suitable for their age and size. For each passenger unrestrained, the driver will receive an additional penalty of $344 and three demerit points, six in double demerit periods.

Passengers aged 16 years and older who do not use an available seatbelt will also be fined $344 if they do not wear a seatbelt.