The video link below is the result of simply not paying attention. As you can see with a camera on the back and front of the vehicle, the driver collided with vehicle at 60 miles per hour. Rounded up, you are traveling 1.5 times your speed at feet per second. For example, at 10 miles per hour, that would be 10 plus, half of ten (five). Thus, you are travelling at 15 feet per second.
At 60 miles per hour, half of 60 is 30, plus 60. That means in one second, you traveled 90 feet. Two seconds, 180 feet. Thus, if you are travelling 60 miles per hour and take your eyes off the road for two seconds, you traveled 180 feet, and if you like to tail gate, that is how much time you have to react.
Keep that in mind. Follow this link for the video or click the photo below.