Inattentive driving involving cell phones accounts for more than a quarter of all car crashes in the U.S. , according to a new study out Monday. The National Safety Council estimated that 21 percent of all crashes (1.2 million out of 5.7 million collisions in 2013) were attributable to cell phone use. And texting while driving could account for another 6 to 16 percent of the total, raising the actual percentage of crashes involving cell phones from 27 percent to 37 percent, the non-profit group said in a report.