That means looking ahead the distance you will travel in 12 to 15 seconds. At lower speeds, that's about one block. At highway speeds it's about a quarter of a mile. If you're not looking that far ahead, you may have to stop too quickly or make quick lane changes. Looking 12 to 15 seconds ahead doesn't mean not paying attention to things that are closer.
Good drivers shift their attention back and forth, near and far.
Look for Traffic. Look for vehicles coming onto the highway, into your lane, or turning. Watch for brakelights from slowing vehicles. By seeing these things far enough ahead, you can change your speed or change lanes if necessary to avoid a problem. Look for Road Conditions.