The average cost of comprehensive car insurance rose by 14.2% in the second quarter of 2010, compared with increases of 4.3% and 6.3% in the two previous quarters.
According to the Confused.com/EMB Car Insurance Price Index, £74 was added to the average premium in the three months to the end of June, with an annual increase of 31% costing £142.
The biggest quarterly shock was felt by 41-55 year olds because of the tendency for children to be included on policies.
Women suffered the worst, with female drivers of this age group facing a 14% penalty for having named drivers, other than their husbands.
Manchester and Merseyside, Inner London and Northern Ireland experienced the largest regional rises and the research revealed that the typical comprehensive premium now stands at £599.
Confused.com product director, Simon Lamble, comments: “This is a massive blow for motorists who have already suffered at the hands of petrol price hikes and insurance premium tax increases.”
He is expecting worse to come because price comparison sites have driven up competition and forced insurers to repeatedly slash their margins.
In January, Zurich announced that it was looking to raise prices by up to 20% and Mr Lamble is expecting the rest of the industry to follow suit, in a bid to get back to profit.