3 ms·

The braking distance increases with velocity. The measurement is in seconds, not feet.

• mikeash 10y ago
  Following time and following distance are linearly related. Either way, it's less than half.
  • sverige 10y ago
    Braking distance is not linearly related to following distance. Braking distance is what is being referred to here.
    • mikeash 10y ago
      They're pretty clearly talking about following distance there.