Research led by Psychology researchers at the University of Warwick reveals that mobile telephone conversations impair drivers' visual attention to such a degree that it can add over 5 metres to the braking distance of a car travelling at 60 miles and causes almost twice as many errors as drivers driving without the distraction of a mobile phone conversation. Dr Melina Kunar, from the University of Warwicks Department of Psychology, and Dr Todd Horowitz, from Harvard Medical School, ran a number of experiments in which the participants had to pay attention and respond (by pressing one of two keys on a keyboard) to a series of discs moving around a computer screen. Some of the participants carried out the task with no distraction. Others carried out the task while also using speaker phones to simultaneously engage in a normal phone conversation, discussing things such as their hobbies and interests. The researchers found that on average the reaction times of those engaging in the hands free telephone conversation were 212 milliseconds slower than those who undertook the task without the simultaneous telephone conversation. A car travelling at 60 miles an hour would travel 5.7 metres (18.7 feet) in that time so the distracting conversation would obviously increase any braking distance at that speed by the same amount. The test participants who were distracted by a phone conversation also made 83% more errors in the task than those not in phone conversations. The researchers also looked at the effect the hands free telephone conversations had on visual attention if the phone conversation was skewed to a more passively orientated task. To do so they asked the test participants to listen over the speaker phones to a series of words and to repeat each word in turn. The research team also looked at the effect of a much more complicated conversational task in which the test participants had to listen to a series of words and after each word then think of and say a new word which began with the last letter of the word they had just heard. Read more here. I know I try to minimize chatting on my mobile while I drive...I don't trust my ability to multitask, and I drive a stick (so I can't hold the phone and shift easily. Many of the erratic drivers I see on the road are chatting happily on their cells. Have you had any problems chatting and driving? Should cell phone driving be outlawed?