One study in South Africa on cell phones and road safety revealed that out of every 4 car crashes, one is cell phone related. Another study of circa 800 international drivers with cell phones found that half swerved or drifted into another lane, 23% had tailgated, 21% cut someone off and 18% nearly hit another vehicle while using the phone. Finally, studies suggest that talking on a phone, no matter how it's done, sharply increases the risk of an accident. Researchers studying brain imaging documented that listening alone reduces the amount of brain activity associated with driving by 37%.
As such, South Africa and other countries have banned the use of cell phones and communication devices that cannot be operated by way of hands-free devices or kits.