At 65mph, you cover two car lengths (~30 ft) in about 1/3 of a second.
Typically human reaction time for braking is about 1.5 seconds.
If something went seriously wrong in front of you (like a sideways car, or a hidden obstacle in front of the car in front of you) you would have covered 10 car lengths before your foot touches the brake pedal.
At 65mph, you cover two car lengths (~30 ft) in about 1/3 of a second.
Typically human reaction time for braking is about 1.5 seconds.
If something went seriously wrong in front of you (like a sideways car, or a hidden obstacle in front of the car in front of you) you would have covered 10 car lengths before your foot touches the brake pedal.