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Your Driving, the Road, and
Your Vehicle
Defensive Driving
The best advice anyone can give about driving is:
Drive defensively.
Please start with a very important safety device in your
vehicle: Buckle up. See
Safety Belts: They Are for
Everyone on page 1-22.
Defensive driving really means “be ready for anything.”
On city streets, rural roads or freeways, it means
“always expect the unexpected.” Rear-end
collisions are about the most preventable of
accidents. Yet they are common. Allow enough following
distance. It’s the best defensive driving maneuver,
in both city and rural driving. You never know when
the vehicle in front of you is going
to brake or turn
suddenly.
Defensive driving requires that a driver concentrate on
the driving task. Anything that distracts from the
driving task
- such as concentrating on a cellular
telephone call, reading, or reaching for something on
the floor
- makes proper defensive driving more difficult
and can even cause a collision, with resulting injury.
Ask a passenger
to help do things like this, or pull off the
road
in a safe place to do them yourself. These simple
defensive driving techniques could save your life.
Assume that pedestrians or other drivers are going to
be careless and make mistakes. Anticipate what
they might
do. Be ready for their mistakes.
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Drunken Driving
Death and injury associated with drinking and driving is
a national tragedy.
It’s the number one contributor to
the highway death toll, claiming thousands of victims
every year.
Alcohol affects four things that anyone needs to
drive a vehicle:
Judgment
Muscular Coordination
Vision
Attentiveness.
Police records show that almost half of all motor
vehicle-related deaths involve alcohol. In most cases,
these deaths are the result
of someone who was
drinking and driving. In recent years, more than
16,000 annual motor vehicle-related deaths have been
associated with the use of alcohol, with more than
300,000 people injured. Many adults
- by some estimates, nearly
half the adult
population
- choose never to drink alcohol, so they
never drive after drinking. For persons under
21,
it’s against the law in every U.S. state to drink alcohol.
There are good medical, psychological and
developmental reasons for these laws.
The obvious way
to eliminate the leading highway
safety problem
is for people never to drink alcohol
and then drive. But what
if people do? How much is
“too much” if someone plans to drive? It’s a lot less than
many might think. Although
it depends on each person
and situation, here is some general information on
the problem.
The Blood Alcohol Concentration (BAC) of someone
who is drinking depends upon four things:
The amount of alcohol consumed
0 The drinker’s body weight
e The amount of food that is consumed before and
during drinking
consume the alcohol.
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According to the American Medical Association,
a
180 Ib (82 kg) person who drinks three 12 ounce
(355 ml) bottles of beer in an hour will end up with a
BAC of about
0.06 percent. The person would reach the
same BAC by drinking three 4 ounce (120 ml) glasses
of wine
or three mixed drinks if each had 1 - 1/2 ounces
(45 ml) of a liquor like whiskey, gin or vodka. It’s
the amount
of alcohol that counts. For example,
if the same person drank three double martinis
(3 ounces or 90 ml of liquor each) within an hour,
the person’s BAC would be close to
0.12 percent.
A person who consumes food just before or during
drinking will have a somewhat lower BAC level.
There is a gender difference, too. Women generally
have a lower relative percentage of body water
than men. Since alcohol is carried in body water, this
means that a woman generally will reach a higher
BAC level than a man of her same body weight when
each has the same number of drinks.
The law in an increasing number of
U.S. states, and
throughout Canada, sets the legal limit at 0.08 percent.
In some other countries, the limit is even lower. For
example, it is 0.05 percent in both France and Germany.
The BAC limit for all commercial drivers in the United
States is 0.04 percent.
The BAC will be over
0.10 percent after three to
six drinks (in one hour). Of course, as we’ve seen,
it depends on how much alcohol is in the drinks,
and how quickly the person drinks them.
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But the ability to drive is affected well below a BAC of
0.10 percent. Research shows that the driving skills
of many people are impaired at a BAC approaching
0.05 percent, and that the effects are worse at night. All
drivers are impaired at BAC levels above 0.05 percent.
Statistics show that the chance
of being in a collision
increases sharply for drivers who have a BAC of
0.05 percent or above.
A driver with a BAC level of
0.06 percent has doubled his or her chance of having a
collision. At a BAC level of 0.10 percent, the chance
of this driver having a collision is 12 times greater; at a
level of 0.15 percent, the chance is 25 times greater!
The body takes about an hour to rid itself of the alcohol
in one drink.
No amount of coffee or number of cold
showers will speed that up.
“1’11 be careful” isn’t the
right answer. What if there’s an emergency, a need to
take sudden action, as when a child darts into the
street?
A person with even a moderate BAC might not
be able to react quickly enough to avoid the collision. rhere’s
something else about drinking and driving that
many people don’t know. Medical research shows
that alcohol in a person’s system can make crash
injuries worse, especially injuries to the brain, spinal
cord or heart. This means that when anyone who
has been drinking
- driver or passenger - is in
a crash, that person’s chance of being killed or
permanently disabled is higher than if the person
had not been drinking.
Drir ng and the1 ing is very dangerous.
Your reflexes, perceptions, attentiveness and
judgement can be affected by even a small
amount of alcohol. You can have a serious
- or
even fatal -collision
if you drive after drinking.
Please don’t drink and drive or ride with a driver
who has been drinking. Ride home in a cab; or
if
not drink.
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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.
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 3/4 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 3/4 of a second, a vehicle
moving at
60 mph (I00 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; the condition
of your brakes; the weight of
the vehicle and the amount of brake force applied.
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Avoid needless heavy braking. Some people drive
in spurts
- heavy acceleration followed by heavy
braking
- rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster
if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you’re driving, brake
normally but don’t pump your brakes.
If you do,
the pedal may get harder to push down.
If your engine
stops, you will still have some power brake assist.
But you will use
it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
Anti-lock Brake System (ABS)
Your vehicle may have anti-lock brakes. ABS is an
advanced electronic braking system that will help prevent a braking skid.
If your vehicle has anti-lock
brakes, this warning light
on the instrument panel will
come on briefly when
you start your vehicle.
When you start your engine, or when you begin to
drive away, your anti-lock brake system will check
itself. You may hear a momentary motor or clicking
noise while this test is going on, and you may even
notice that your brake pedal moves or pulses a little.
This is normal.
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The anti-lock system can change the brake pressure
faster than any driver could. The computer
is
programmed to make the most of available tire and road
conditions. This can help you steer around the obstacle
while braking hard.
Let’s say the road is wet and you’re driving safely.
Suddenly, an animal jumps out in front
of you. You slam
on the brakes and continue braking. Here’s what
happens with
ABS:
A computer senses that wheels are slowing down.
If one
of the wheels is about to stop rolling, the computer
will separately work the brakes at each wheel. As you brake, your computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly.
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Remember: Anti-lock doesn’t change the time you need
to get your foot up to the brake pedal or always
decrease stopping distance.
If you get too close to the
vehicle in front of you, you won’t have time to apply
your brakes
if that vehicle suddenly slows or stops.
Always leave enough room up ahead to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Don’t pump the brakes. Just hold the brake pedal down
firmly and let anti-lock work for you. You may feel a
slight brake pedal pulsation or notice some noise,
but this is normal.
Braking in Emergencies
At some time, nearly every driver gets into a situation
that requires hard braking.
If you have anti-lock, you can steer and brake at the
same time. However,
if you don’t have anti-lock,
your first reaction
- to hit the brake pedal hard
and hold it down
- mav be the wronq thina to do. Your
wheels can stop rolling. Once they do, the vehicle
can’t respond to your steering. Momentum will carry
it in whatever direction it was headed when the wheels
stopped rolling. That could be off the road, into the
very thing you were trying to avoid, or into traffic.
If you don’t have anti-lock, use a “squeeze” braking
technique. This will give you maximum braking while
maintaining steering control. You can do this by pushing
on the brake pedal with steadily increasing pressure.
In an emergency, you will probably want to squeeze
the brakes hard without locking the wheels. If you hear
or feel the wheels sliding, ease
off the brake pedal.
This will help you retain steering control.
If you do have
anti-lock, it’s different. See “Anti-Lock Brakes.”
In many emergencies, steering can help you more than
even the very best braking.
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