The Governors Highway Safety Association study analysed more than 350 scientific papers on distracted driving published between 2000 and 2011.
From the research, it concluded that drivers are no less distracted when using hands-free than when talking on a hand-held phone.
It did, however, report that texting while driving is most likely riskier than simply talking on the phone.
Despite the increased level of distraction, the study also found that in dangerous driving situations, the average driver paid less attention to their phone conversation and focused more on the road, bringing their level of concentration close to that of a driver who was not using a phone.
Although it acknowledged the increased risk of using a phone while driving, the Governors Highway Safety Association believes states should conduct more research before completely banning the practice.
Using a phone while driving is banned in nine US states and texting while driving is banned in 34.
The report encouraged greater investment into road surface safety features like rumble strips, as well as the implementation of distracted driver communication programs and distracted driving policies and programs for workplaces.
In Australia it is illegal to touch a phone while you are behind the wheel of a car with the ignition on.
What do you make of the findings? Do you agree that using hands-free is just as distracting as using a hand-held device? And should phone bans exist, or are they unnecessary? Let us know your thoughts in the comments section below.