A new, national report indicates up to half of all accidents are caused by “distracted drivers.” Scott Falb of the Iowa D-O-T believes that circumstance is under-reported in the state because the official stats indicate just five-percent of accidents are caused by a distracted driver.He says 51-percent of the crashes list unknown and another 23-percent list unapparent.Falb says proving a driver was distracted can be difficult. He says officers have to have solid evidence that the driver was distracted.Falb says unfortunately, drivers are not always concentrating on the task at hand.Falb says there are more cars on the road and fewer drivers paying attention.