Think about how often you glance away from the road while driving. Some glances may be innocuous and necessary, such as checking your blind spot before a lane change. Looking in the rear view mirror to see if someone is riding your bumper, or just checking out what is causing a stoppage in a particular lane.
But when we take our eyes off the road for things that are not imitable for driving safety, such as changing a radio station, checking or sending a text message or even entering numbers to dial a phone, this could lead to devastating accidents. This possibility is especially important given how drivers who look away from the road for two seconds while travelling at 70 miles per hour, for instance.
A car going at that speed will travel more than half the length of a football field in two seconds; which is why researchers at the National Highway Traffic Safety Administration suggested publicly that glances away from the road should be two seconds or less.