manilva15b wrote:Guidelines also say two seconds in good weather and four in rain (doubled for HGVs)
Scenario 1. Car B is following car A at 70 mph with a .67s gap (Highway Code thinking distance), or even a 2s gap to allow for reduced neurons.
Car A brakes "suddenly" and comes to a stop say the HC distance of 75m further down the road. Allowing for thinking distance, car B brakes and comes to a comfortable stop without hitting car A (assuming car A doesn't have Porsche ceramic brakes..).
Scenario 2. The same as scenario 1, except it's wet. Assume the same 2 second gap for thinking time. (Not 4 seconds). Car A brakes and stops in let's accept twice the dry stopping distance = 150m. Car B reacts within his thinking time of 2 seconds and brakes also at 150m, missing the rear of car A.
Why does the book say double your following distance in the wet, when your thinking time is the same and your braking distances are both doubled (i.e the same)?
What am I not understanding here?