Research revealed that using a mobile phone while driving is as dangerous as driving while intoxicated, and mobile phone use while driving is far more prevalent than drunk-driving. This is because talking and driving at the same time lowers the driver's reflexes thus, causing them to react slowly and avoid other drivers.

Moreover, a study in The New England Journal of Medicine reports that drivers who used mobile phones while driving were four times more likely to crash than those who don't, a rate equal to that for drunken driving at the 0.08 g/dL blood alcohol concentration (BAC) level.

Furthermore, many studies argue that the increased "cognitive workload" involved in holding a conversation is the real danger and not the use of hands.

As these studies deal with the effect of using mobile phones in driving performance, the approach taken to lessen the is to use hands-free phones. However, the major problem is that the person with whom the driver is conversing cannot see the traffic situation and therefore does not regulate their level of conversation to allow the driver to concentrate.

A study carried out by the University of Utah found that hands-free devices do not reduce the distraction caused by talking on a mobile phone. This fact was supported by the study published in the British Medical Journal funded by the Insurance Institute for Highway Safety wherein they found out that there was only a slight safety benefit from using a hands-free phone. Thus, even drivers who use hands-free model cell phones are four times as likely to be involved in accidents involving a serious injury than on drivers who do not use cell phones.

In terms of public safety, it's probably correct to say that banning cell phones would reduce the number of accidents. In the United Kingdom, from 27 February 2007, motorists who are caught using a hand-held mobile phone while driving will have three penalty points added to their license in addition to the fine of ?60. This was introduced to try to stem the increase in drivers ignoring the law.

However, in New York and Connecticut banning cell phone use while driving was proven to be ineffective due to a lack of visible enforcement. The percentage of offenders decreased from 2.3% to 1.1% immediately after the ban was implemented, but after being in effect for a year the percentage increased to 2.1%, which is not significantly different from the pre-ban figure. It was then concluded that banning cell phone use is not enough instead, a strong enforcement campaigns accompanied by publicity is needed to achieve longer term compliance.