Control Of A Vehicle; Braking - GMC 1993 Safari Owner's Manual

Control of a Vehicle
You have three systems that make your vehicle go where you want it to go.
They are the brakes, the steering and the accelerator. All three systems have
to do their work at the places where the tires meet the road.
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Sometimes, as when you're driving on snow or ice, it's easy to ask more of
those control systems than the tires and road can provide. That means you
can lose control of your vehicle.
Braking
Braking action involves perception time and reaction time.
First, you have to decide to push on the brake pedal. That's perception
time. Then you have to bring up your foot and do it. That's reaction time.
Average reaction time is about 314 of a second. But that's only an average.
It might be less with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness, coordination, and
eyesight all play a part. So do alcohol, drugs and frustration. But even in
314 of a second, a vehicle moving at 60 mph (100 km/h) travels 66 feet
(20 m). That could be a lot of distance in an emergency, so keeping enough
space between your vehicle and others is important.
And, of course, actual stopping distances vary greatly with the surface of the
road (whether it's pavement
or
gravel); the condition of the road (wet, dry,
icy); tire tread; and the condition of your brakes.
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