> If you think putting sufficient distance between you and the car in front is vague, you are a poorly educated driver and most likely a dangerous one.

Huh? The whole context of this discussion starting from js2's comment is about exactly how far is should be, and in particular whether 2 seconds or 4 seconds (which at highway speeds is 50 yards vs. 100 yards) is more reasonable as a rule of thumb. As you can see from my link, most government safety organizations recommend 2 or 3 seconds in good weather.