Two-second rule two seconds as inadequate, and recommend a three-second rule. German law requires a minimum 0.9 second distance but when tested under relaxed conditions researchers found that their test subjects spent 41% of the test time at following distances under 0.9 second. 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
Equal authenticity rule Equal authenticity rule The equal authenticity rule is a rule of judicial interpretation developed by Canadian courts as a way of interpreting laws which are written in two parallel texts in English and French. The constitution of Canada requires that both versions of each Canadian law be treated as equally authoritative, which can result in problems when the English and French versions do not say exactly the same thing. The equal authenticity rule is derived from section 133 of the "Constitution Act, 1867", which states, "inter alia", "The Acts of the Parliament of Canada and the Legislature of Quebec shall