Using mobile phones can cause drivers to take their eyes off the road, their
hands off the steering wheel, and their minds off the road and the surrounding
situation. It is this type of distraction – known as cognitive distraction – which
appears to have the biggest impact on driving behaviour. There is a growing
body of evidence that shows that the distraction caused by mobile phones
can impair performance in a number of ways, e.g. longer reaction times
(notably braking reaction time, but also reaction to traffic signals), impaired
ability to keep in the correct lane, shorter following distances, and an overall
reduction in awareness of the driving situation.