Insurance group Direct Line said today that one in five young drivers insured with the group are agreeing to install “black boxes” in their cars to monitor their driving skills and cut costs on premiums.

Direct Line, which also includes Churchill and Privilege, said it was installing telematics technology in around 400 vehicles a week and had rolled it out in a total of 6,000 so far since launch in June across its insurance brands.

The so-called black boxes are available for drivers aged 17 to 25 and offer an initial discount of 20% on their premium, with their renewal price then based on the results gathered from the system over the first year.

Direct Line also offers an app to assess behaviour on the road, which can reduce premiums by up to 10%.

Telematics monitor a driver’s speed, braking, accelerating and cornering and Direct Line said it believes they will become “increasingly important in the UK motor market”.

Details of the black box roll out came as Direct Line Group announced third quarter results revealing a 6.1% rise in operating profits to £131.2million thanks to lower costs and a sharp drop in weather-related claims.

The group said this week’s St Jude’s storm saw its call centres handle more than twice the normal volume of enquiries from policyholders.

While it stressed it was too early to assess the final cost of claims related to the storm, it believes they will be covered within the £25 million overall expected for weather events throughout the last three months of the year.

Direct Line said gross written premiums in its motor insurance arm fell 12% in the third quarter to £386 million as it suffered in a “highly competitive” market.

It said it had cut average motor premiums by 5%, thanks to cost savings as bodily injury claims reduce due in part to recent legal reforms.

Direct Line, which also owns the Green Flag breakdown service, was spun off last year by Royal Bank of Scotland, which still owns 28.5% of the group.