Crashes have cost the Bay of Plenty District Health Board $1.35m in 2017.
In that year, more than 110 people were admitted to hospitals due to car crash trauma in the region.
In the wider midlands region - Waikato, Bay of Plenty, Lakes, Taranaki and Tairawhiti - that number was 549 collectively.
About 16 per cent of those were not wearing a seatbelt when they were injured, according to the health board, which had compiled the figures for Road Safety Week this week.
Clinical nurse trauma specialist Katrina O'Leary said the focus of the week was improving seatbelt use as it was still an issue.
"Road traffic accidents remain the second most common cause for injury admission to hospitals and are the most common cause of admission for serious injury.
"Lack of seatbelt use increases the likelihood of serious injury, especially if ejected from the vehicle."