The social cost of road crash injuries and fatalities dropped by about $48 million in Rotorua between 2010 and 2011.
Figures released by the Ministry of Transport revealed road injuries and deaths cost the community $52.2 million in 2011, almost half of the previous year's total of $100.1 million. Figures for 2012 are not yet available.
The cost includes medical, legal and vehicle damage costs. Loss of life, reduced life quality and the impact of temporary or permanent disabilities caused by crash injuries are also factored in.
Bay of Plenty road policing manager Inspector Kevin Taylor said the figures reflected a clampdown on speeding drivers.
"Because people are driving slower across the general motoring population, when those crashes occur, statistically there is less harm occurring.''
In total, 156 crashes occurred in Rotorua in 2011, which resulted in 212 casualties. Of these, three were fatal and 33 were serious injuries.
In 2010, 152 crashes occurred, which resulted in 12 deaths. This was up from 143 crashes and five deaths in 2009.
Injuries and fatalities from 373 crashes in Hawke's Bay had a social cost of $144.2 million in 2011. More than 100 crashes occurred in Wanganui, and cost $26.9 million for the year.
Mr Taylor expected the social cost of 2012 crashes in Rotorua to be similar to 2011.
"Rotorua in 2012 had a particularly good year.
"There were still a number of fatalities, but it was fewer than previous years.''
There is still room for improvement, he said.
"It has to become socially unacceptable to drink and drive and to speed. Once we've got that then more people are going to survive on our roads and fewer people are going to go to hospital, and the social cost will continue to decrease.''
Nationally, the social cost of road crashes in 2011 amounted to about $3.14 billion, down from $3.67 billion in 2010.
Transport Ministry chief executive Martin Matthews said the reduction was largely due to a 24 per cent drop in the road toll between the two years.
In 2011, 284 people died on the roads, down from 375 in 2010.
The 2011 figure translated to a rate of 6.4 deaths per 100,000 people _ the lowest rate in 60 years, Mr Matthews said.
It is encouraging but still too high, he said.
"To give a sense of the size of the cost, $3.14 billion is almost the equivalent of a month's worth of New Zealand's exports.
"Over 90 per cent of the total social cost is related to loss of life or permanent disability,'' Mr Matthews said.
Despite the low road toll, a person is killed on the roads every 31 hours on average, he said.