“In the UK sample, there was a range of different types of secondary task observed during driving, with nearly three-quarters of the trips viewed containing at least one secondary task interaction (73%). Almost all drivers (92%) engaged in a non-driving-related task in at least one out of the 15 trips coded for them, showing that distraction from the driving task is a frequent and common occurrence. Mobile phone use was the most common secondary task in terms of proportion of drivers engaging with it (69%).”
69% of drivers using mobile phones in the UDrive research where they mounted multiple cameras in cars. So, despite knowing they were being filmed, from multiple angles, they still used their phones!