Cell phone users drive `blind' : study explains why hands-free phone just as bad as hand held.

Due to 'inattention blindness' drivers react more slowly and are more accident prone when they are talking on cell phones, whether or not the phones are hand held or hands free, than drivers not conversing on cell phones. A study undertaken at the University of Utah involved four experiments with a driving simulator. Each of the experiments found the driving performance of those holding conversations on cell phones to be impaired. Situations tested include braking performance (which worsened as traffic increased), attention to the driving environment, verification of the idea that drivers using cell phones look at their surroundings but don't really see them, and implicit perceptual memory. In each case, the drivers using cell phones had worse driving performance than those not holding conversations on cell phones did.