The cost of auto insurance claims is rising, according to data released by the Insurance Research Council, ending a trend of stable or shrinking costs that was powered by declining claim frequency.

While individual claims were growing more expensive in recent years, there were significantly fewer. In the case of bodily injury liability claims, for instance, 2010 was the first year since 1994 that claims did not decline. That offset the increased cost of claims in the past.

"These are not encouraging findings for insurers or drivers," said Elizabeth Sprinkel, senior vice president of the American Institute For Chartered Property Casualty Underwriters. "While we hope these findings represent temporary conditions, we can’t be sure that is the case and can’t afford to ignore the factors driving rising claim costs."

According to the report, the growth is largely due to higher personal injury protection (PIP) costs, especially in New York, Florida and Michigan. These three states have seen major cost increases, which researchers believe is resulting at least partly from claims abuse and insurance fraud. PIP claim severity and cost have both gone up recently.