There was a "staggering" 18% rise in road accident personal injury claims last year, a report has shown.
The increase came despite an 11% fall in road accidents and is likely to mean a rise in insurance premiums for drivers, the report from the Actuarial Profession revealed.
The year-on-year rise in bodily-injury claims between 2010 and 2011 was the highest ever, with the increase adding about £400 million to insurers' costs last year, said the report.
There appeared to be a "clear correlation" between location of claims management companies' offices and the "hotspots" for personal injury claims, said David Brown, the chairman of the working party which produced the report.
With legislation expected soon affecting the way claims companies do business, the big rise in bodily-injury claims last year may have been "a last hurrah", Mr Brown said.
Most bodily-injury claims last year came from people in north-west England, with this area overtaking the worst regions of the US in terms of the proportion of accidents involving a bodily-injury claim. There were a particularly large number of claims from Liverpool, Manchester and Birmingham.
Mr Brown said: "The increase in costs to insurers because of the rise in bodily-injury claims is likely to result in a rise in motor insurance premiums for drivers. The clear correlation between claims management companies' office locations and the 'hotspots' for bodily injury claims suggests that the two are interlinked."
He went on: "We expect to see legislation coming soon which will affect the way in which claims management companies do business, which may account for the significant increase seen in 2011. It is possible this is a last hurrah."
Last year, the Government proposed a ban on referral fees - a system in which personal injury details are sold on by insurance companies to lawyers.
The Actuarial Profession said that the proposal had not yet passed into law and there was "currently no recognised definition of a referral fee". It added that there was "some way to go before insurance companies stop losing money on private motor insurance policies, and so premium increases are unlikely to be a thing of the past".