Young drivers have seen insurance costs increase by 14% in the last three months, new figures from motoring organisation AA are expected to reveal.
The data, which will be published on 27 January, is expected to show that the cost of car insurance for 17 to 22-year-olds is accelerating.
Costs have also risen for parents aged from 40 to 49 because they put children as named drivers on their policies.
Scotland is expected to show the lowest increase in car insurance costs.
Overall in the UK, the average cost of car insurance is expected to have risen by 11% in the last three months.
Young male drivers who have just passed their tests are bearing the brunt of the increases, according to underwriters. Quoted premiums have been marked up by at least a third compared with a year ago.
Few providers are offering male, first-time drivers a quote of under £3,500 a year. Third party fire and theft cover is not much cheaper than comprehensive, because the main problem is injuries caused by accidents.
More insurers are refusing to insure young people, or charge rates that price them out of the market.
The rising costs are explained in part because claims are getting bigger. Experts say there is a particular problem with young drivers crashing with their friends in the car with them - accidents that lead to large liability payouts.