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
Sometimes, as when you are driving on snow or ice, it
is 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 action involves perception time and
First, you have to decide to push on the brake pedal.
That is perception time. Then you have to bring up your
foot and do it. That is reaction time.
Average reaction time is about 3/4 of a second. But that
is 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 3/4 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
And, of course, actual stopping distances vary greatly
with the surface of the road (whether it is pavement
or gravel); the condition of the road (wet, dry, icy); tire
tread; the condition of your brakes; the weight of
the vehicle and the amount of brake force applied.