The MythBusters The MythBusters

MythBusters Episode 232: Dangerous Driving

Premier Date: August 8, 2015

It is just as dangerous to use a cell phone hands-free while driving as it is to use a cell phone while holding it.


Initial testing was done at the Alameda runway on a course that Adam and Jamie had not seen before. To isolate the variable of learning the course, Adam ran the course “hands-full” first, followed by hands-free, while Jamie did the inverse. For each run, the driver was asked a series of different types of questions meant to stimulate different areas of the brain used in driving. The results were overwhelmingly in favor of the myth: neither passed either run, both did better on their second run regardless of technique, and the average scores for each technique were nearly identical.

Feeling that the course lacked realism (due to the lack of traffic) and that they weren’t representative of someone with average driving skills, Adam and Jamie set up additional testing in a driving simulator at Stanford University, with the help of 30 volunteers (15 for each technique). Only 1 volunteer for each technique successfully completed the run, and the others failed at a near-identical ratio across techniques. Additionally, an eye-tracking system used to measure the distraction of the volunteers quantitatively showed that drivers looked away from the road for an identical amount of time regardless of technique. With a significant amount of evidence showing no difference between hands-full and hands-free, Adam and Jamie declared the myth confirmed.

It is easy for someone to drive a vehicle in reverse at high speed.


An early test proved that it was possible to go to highway speeds in reverse, as long as the driver was driving perfectly straight, but the unstable equilibrium of the car’s steering in reverse meant that real road tests would be more difficult. Initially, both Adam and Jamie had significant difficulty in driving the car in reverse on the road course, but advice from an instructor and a shift in technique (having the driver position himself in the center of the car and look backward through the rear windshield) made the task surprisingly easy. A final test, with Adam driving in reverse and Jamie chasing Adam in a car driving forward, had Adam successfully evade Jamie for some time before being caught. Because Adam was caught, they couldn’t call the myth confirmed, but the surprising ease of the task otherwise allowed the two to call the myth plausible.