It happens in the blink of an eye. This is why you stay alert.
I’m driving, with passengers, on a freeway that is moving briskly. There is a sudden commotion a few hundred yards ahead, it’s hard to see what happens, but a car shoots out tumbling to the right, a truck bucks and swerves as it brakes heavily, a bus rocks like it was kicked. Other brake lights come on and traffic slows. I worry about the drivers behind me, but they manage to brake on time, too. By the time we reach the scene, the people directly involved are on the side of the road, on their cell phones and starting to get out of their vehicles.
I’ve seen this two or three times in the past couple of years.
Once upon a time I was a passenger in a car where the driver was following very close indeed (say, a car length), in 65 mile an hour traffic. I told the person it would be a good idea to get more distance.
“Why? It’s not like they’re going to slow down suddenly.”
I heard of an older driver once who never used the radio. “Too much of a distraction,” he said.
Pay attention, stay alert.