Scientists have finally proven that talking on a hands-free mobile phone is more distracting and potentially more dangerous than having a conversation with passengers.

Fleet managers who have introduced total bans on mobile phone use in cars have often encountered opposition from drivers who claim it cannot be any more distracting than having a conversation with rear seat passengers.

But research has found that a conversation on a hands-free phone requires more mental effort due to the lack of proximity, the extra effort involved in working out pauses and tone and the fact that the person on the other end of the line cannot react to changing road conditions to help the driver as a passenger can.

It is the first comprehensive research carried out in the UK looking at how the potential dangers of using hands-free phone kits and talking to passengers compare.

Hinting that fleets may want to take heed of the findings, possibly with a view to a total ban on mobile phone conversations while driving, the report’s authors said: “The research may be particularly relevant to companies where employees use phones for work, and may wish to develop policies regarding phone use.”

The study, called Conversations in car: the relative hazards of mobile phones and conducted by the Transport Research Laboratory (TRL) for the Department for Transport, also found more variations in speed when talking on the phone, with motorists often driving faster, while the ability to safely follow cars lessened.

Aside from the safety aspect, TRL also found the quality of information exchanged and decision-making deteriorated markedly.

It noted that this could have a serious detrimental effect on work discussions.

It concluded: “One clear implication is that using a mobile phone via a hands-free kit while driving is not equivalent to talking to a passenger.

“It is a much more difficult task. The obvious conclusion is that it is not worth the increased potential risk of using a hands-free carphone.”

TRL recommends that the DfT should consider including hands-free systems in any future legislation concerning banning the use of mobile phones.

  • The report, priced at £40, is available from TRL by calling 01344 770783.