On my way back from Kentucky yesterday, I had a close encounter with one of those all-too-common airhead drivers. It happened like this:
I'm on I-75, southbound. It's two lanes in each direction and I'm going down a long steep hill when I find myself between an 18-wheeler and a concrete wall. The van ahead of me passed the truck but then matched the truck's speed keeping me beside it. Then the airhead pulls up behind me so close I can't see the front of her car in any of my mirrors. I guess she was within six or eight feet of my back bumper. I tapped the brake pedal to flash the brake lights. That usually works, but not this time. I have some really bright LED's back there, but airhead didn't notice! She just moved in a little closer! Finally, at the bottom of the hill the truck slowed and the van moved out of the way and I got back in the right lane so she could pass.

Some people don't have a clue about what could happen. If I had slowed slightly, there would have been a three or four vehicle pileup before airhead could even get her foot on the brake. Usually, tailgaters are trying to intimedate you into speeding up, but I had nowhere to go. The Interstate speed limit in Kentucky is 65, but everybody was going about 70. At those speeds a normal 3/4 second reaction time allows you to travel several car lengths(about 30 meters) before you can go from the gas to the brake.
Howard