> The two-second rule tells a defensive driver the minimum distance needed to reduce the risk of collision under ideal driving conditions. The allotted two-seconds is a safety buffer, to allow the following driver time to respond. [emphasis mine]

> Some authorities regard two seconds as inadequate, and recommend a three-second rule. […] The United States National Safety Council suggests that a three-second rule—with increases of one second per factor of driving difficulty—is more appropriate. Factors that make driving more difficult include poor lighting conditions (dawn and dusk are the most common); inclement weather (ice, rain, snow, fog, etc.), adverse traffic mix (heavy vehicles, slow vehicles, impaired drivers, pedestrians, bicyclists, etc.), and personal condition (fatigue, sleepiness, drug-related loss of response time, distracting thoughts, etc.). For example, a fatigued driver piloting a car in rainy weather at dusk would do well to observe a six-second following distance, rather than the basic three-second gap.

I've had to veer to avoid accidents. At least three sitautions I can remember on the interstate: a semi truck tire blowout in front of me leaving large parts of the tire in my lane; a bike rack with several bikes falling off the back of a car in front of me; a truck in front of me veering around a obstacle (it appeared to be a pickup truck bed liner) I was blind to because I couldn't see beyond the truck in front of me.

I was lucky to avoid all of these because I had a parallel lane or shoulder I could escape into. When I drive now, if it's congested I leave extra following diatance. If that reduces the road capacity so be it. Compared to drivers who follow much too closely (which itself causes sudden slowdowns since they tend to over brake) or who drive in the wrong lane for their speed, I don't think I'm the person you need to worry about.

FWIW, I haven't been in an accident in over 25 years.