New data suggests the risk of an accident almost doubles when using a mobile phone at the wheel.
Data was gathered on more than 4,000 drivers over a period of 18 months, including on journeys made with hands-free and illegal hand-held mobile phone use, with the results suggesting that driver performance is affected in both scenarios.
Hard braking events - G-force sufficient to propel a handbag on to the floor - occur approximately once every 50 miles with an average driver, but the survey established that for drivers using a hand-held mobile, these events increase by 75%, and 20% for those using hands-free.
The data also revealed that men are almost twice as likely to use their phone illegally at the wheel, while drivers of either sex between the ages of 25 and 35 most frequently commit this offence.
A majority of illegal phonecalls are made on roads with a speed limit of 40mph or less, where accidents are 11 times more likely to occur compared to motorways.
The data also showed that drivers using a phone illegally tend to drop their speed by a third on average, suggesting a high level of distraction.
The survey was carried out by Wunelli, a provider of vehicle telematics for insurance companies, and insurance broker Drivology.
Paul Stacy, founding director of Wunelli, said: “Driving a car is the most dangerous activity most people will ever do. The fact we all started to use phones in our cars 10 years before the Government in the UK banned use while driving, means we need re-think our attitude to mobile phone use, and mute the mobile when we make a journey.”