97.5 % of drivers cannot operate their vehicles safely while using their cell phones. Only a very small percentage of individuals, labelled "supertaskers" can both drive and talk on a cell phone without any ill effects to their driving ability. Most people aren't able to drive and talk on a cell phone at the same time.
Research was conducted analyzing the performance of 200 participants over the single task of driving a simulated car on a virtual road. The participants were then studied after being assigned another, very demanding task -- talking on a cell phone.
The researchers measured performance of participants in four areas of braking reaction time, following distance, memory and their ability to solve math problems.
The research showed that for the majority of people, driving performance suffered while talking even on a hands-free cellphone. It took most people 20% longer to hit their brakes. Most also failed to maintain pace; following distance was increased 30%.
Previous research has indicated that talking on a cell phone while driving leads to inattention blindness in drivers. They fail to see up to half the information in the driving environment that they would have had they not been talking on their cellphones.
The National Safety Council estimates that 28% of all accidents and deaths on U.S. highways involved talking on cell phones and driving.