BLACKSBURG, VA — Distracted driving is the No. 1 cause of car crashes, according to the Occupational Safety and Health Administration. A Virginia Tech Transportation Institute study — an ongoing project at the Virginia Tech Transportation Institute to study how crashes happen — has revealed just how dangerous distracted drivers can be. Virginia Tech University researchers put four cameras in 100 cars for a year and recorded what happened, according to the Web site www.nbc4.tv. Following 241 drivers who clocked 2 million miles on the road, the project recorded 82 crashes, 761 near-crashes, and more than 8,000 other in-cidents where a driver had to make a sudden move, like stopping or swerving. Researchers say the main cause is drivers simply not paying attention due to distractions such as cell phones, changing the music on a CD player, or just being tired. Nearly 80 percent of the crashes and 65 percent of the near-crashes happened because drivers weren’t paying attention. Researchers said that of the 82 crashes that took place during the study, only 15 were reported to police.