Here's why you're supposed to stay at least three seconds behind the car in front of you when you're driving:
A woman was making a video WHILE she was on the highway, when the car in front of her ran over a two-by-four . . . kicked it up off the road and into the air . . . where it smashed through her windshield like a spear.
According to the YouTube video, the driver is fine, and she was filming the road because the truck next to her was driving aggressively.