Control of a Vehicle Braking
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 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 rime.
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
noving at
60 mph (1 00 kmh) 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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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
and
let anti-lock work for you. You may feel the brakes
vibrate, or you may notice some noise, but this
is
normal. On vehicles with four-wheel drive, your
anti-lock brakes work at all times
-- whether you are in
two-wheel drive
or four-wheel drive.
Braking in Emergencies
Use your anti-lock braking system when you need to.
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help
you more
than even the very best braking.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
Steering Tips
Driving on Curves
It’s important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here’s why:
Experienced driver or beginner, each
of us is subject to
the same laws
of physics when driving on curves. The
traction
of the tires against the road surface makes it
possible for the vehicle to change its path when you turn
the front wheels. If there’s no traction, inertia will keep
the vehicle going
in the same direction. If you’ve ever
tried to steer a vehicle on wet ice, you’ll understand
this.
The traction you can get in a curve depends on the
condition of your tires and
the road surface, the angle at
which
the curve is banked, and your speed. While you’re
in a curve, speed is the one factor you can control.
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Suppose you’re steering through a sharp curve. Then you
suddenly accelerate. Both control systems
-- steering and
acceleration
-- have to do their work where the tires meet
the road. Adding
the sudden acceleration can demand too
much
of those places. You can lose control.
What should
you do if this ever happens? Ease up on the
accelerator pedal, steer the vehicle the way
you want it
to go, and slow down.
Speed limit signs
near curves warn that you should
adjust your speed. Of course,
the posted speeds are
based
on good weather and road conditions. Under less
favorable conditions you’ll want to
go slower.
If you need to reduce your speed as you approach a
curve, do it before you enter the curve, while your front
wheels are straight ahead.
Try
to adjust your speed so you can “drive” through the
curve. Maintain
a reasonable. steady speed. Wait to
accelerate
until you are out of the curve, and then
acce.lerate gently into
the straightaway.
Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a
hill and
find
a truck stopped in your lane, or a car suddenly
pulls
out from nowhere, or a child darts out from
between parked cars and stops right
in front of you.
You can avoid these problems by braking -- if you
can stop in time. But sometimes you can’t; there isn’t
roam. That’s the time
for evasive action -- steering
around the problem.
Your vehicle can perform very well
in emergencies
like these. First apply
your brakes. (See “Braking in
Emergencies” earlier in this section.) It is better to
remove as much speed as you can from a possible
collision. Then steer around the problem,
to the left
or right depending on the space available.
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Road Rea ---:y
An emergency like this requires close attention and a
quick decision. If you are holding
the steering wheel at .
the recommended 9 and 3 o’clock positions, you can
turn it a full
180 degrees very quickly without removing
either hand. But you have
to act fast, steer quickly, and
just as quickly straighten
the wheel once you have
avoided the object.
The fact that such emergency situations are always
possible
is a good reason to practice defensive driving at
all times and wear safety belts properly.
You may find sometime that your right wheels have
dropped off the edge of a road
onto the shoulder while
you’re driving.
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OFF-ROAD RECOVERY RECOVER
0-
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator
and then, if there is nothing in the way, steer
so that your vehicle straddles the edge of the pavement.
You can turn the steering wheel up to one-quarter turn
until the right front tire contacts the pavement edge. Then
turn your steering wheel to go straight down the roadway.
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@ Check your mirrors, glance over your shoulder and
start
your left lane change signal before moving out
of the right lane to pass. When you are far enough
ahead
of the passed vehicle to see its front in your
inside mirror, activate
your right lane change signal
and
move back into the right lane. (Remember that if
your right outside mirror
is convex, the vehicle you
just passed may seem to be farther away from you
than it really is.)
Try not to pass more than one vehicle at a time
on two-lane roads. Reconsider before passing the
next vehicle.
Don’t overtake a slowly moving vehicle too rapidly.
Even though the brake lamps are not flashing,
it may
be slowing down or starting to turn.
If you’re being passed, make it easy for the
following driver to get ahead
of you. Perhaps you
can ease a
little to the right.
Loss of Control
Let’s review what driving experts say about what
happens when the three control systems (brakes, steering
and acceleration) don’t have enough friction where
the
tires meet the road to do what the driver has asked.
In any emergency, don’t give up. Keep trying to
steer and constantly seek an escape route
or area of
less danger.
Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid
most skids by taking reasonable
care suited
to existing conditions, and by not
“overdriving” those conditions.
But skids are always
possible.
The three types
of skids correspond to your vehicle’s
three control systems.
In t.he braking skid, your wheels
aren’t rolling.
In the steering or cornering skid, too
much speed or steering
in a curve causes tires to slip and
lose cornering force. And
in the acceleration skid, too
much throttle causes the driving wheels to spin.
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A cornering skid and an acceleration skid are best
handled by easing your
foot off the accelerator pedal.
If your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly
steer the way you want the
vehicle to go. If you start steering quickly enough, your
vehicle may straighten out. Always be ready for
a
second skid if it occurs.
Of course, traction is reduced when water, snow, ice,
gravel or other material is on the road. For safety,
you’ll
want to slow down and adjust your driving to these
conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving
on a surface with reduced traction, try
your best to avoid sudden steering, acceleration or
braking (including engine braking by shifting
to a lower
gear).
Any sudden changes could cause the tires to
slide. You may not realize the surface is slippery until
your vehicle is skidding. Learn to recognize warning
clues
-- such as enough water, ice or packed snow on
the road
to make a “mirrored surface” -- and slow
down when you have any doubt.
Remember:
Any anti-lock brake system (ABS) helps
avoid
only the braking skid.
Driving Guidelines
Off-Road Driving with Your
Four-Wheel-Drive Vehicle
This off-road guide is for vehicles that have
four-wheel drive.
Also, see “Anti-Lock Brakes” in the Index.
If your vehicle doesn’t have four-wheel drive, you
shouldn’t drive off-road unless you’re on a level,
solid surface.
Off-road driving can be great
fun. But it does have
some definite hazards.
The greatest of these is the
terrain itself.
“Off-roading” means you’ve left
the great North
American road system behind. Traffic lanes aren’t
marked. Curves aren’t banked. There are
no road signs.
Surfxes can
be slippery, rough, uphill or downhill. In
short, you’ve gone right back to nature.
Off-road driving involves some new skills. And that’s
why it’s very important that
you read this guide. You’ll
find many driving tips and suggestions. These
will help
make your off-road driving safer and more enjoyable.
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Controlling your vehicle is the key to successful
off-road driving. One
of the best ways to control your
vehicle
is to control your speed. Here are some things to
keep in mind. At higher speeds:
you approach things faster and you have less time to
you have less time to react.
scm
the terrain
for obstacles.
you have more vehicle bounce when you drive
over obstacles.
you’ll need more distance for braking, especially
since you’re on an unpaved surface.
When you’re driving off-road, bouncing and
quick changes in direction can easily throw you
out of position. This could cause you to lose
control and crash.
So, whether you’re driving on
or off the road, you and your passengers should
wear safety belts.
Scanning the Terrain
Off-road driving can take you over many different
kinds of terrain.
You need to be familiar with the
terrain and its many different features. Here are some
things to consider.
Surface Conditions. Off-roading can take you over
hard-packed dirt, gravel, rocks, grass, sand, mud,
snow
or ice. Each of these surfxes affects the steering,
acceleration and braking
of your vehicle in different
ways. Depending upon the kind of surface
you are
on, you may experience slipping, sliding, wheel
spinning, delayed acceleration, poor traction and
longer braking distances.
Swfuce Obsrdes. Unseen or hidden obstacles can
be hazardous. A rock, log, hole, rut or bump can
startle you
if you’re not prepared for them. Often these
obstacles are hidden by grass, bushes, snow or even
the rise and fall
of the terrain itself. Here are some
things to consider:
Is the path ahead clear?
0 Will the surfxe texture change abruptly up ahead?
Does the travel take you uphill or downhill? (There’s
more discussion of these subjects later.)
0 Will you have to stop suddenly or change
direction quickly?
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When you drive over obstacles or rough terrain, keep a
firm grip on the steering wheel. Ruts, troughs or other
surfax features can jerk the wheel out of your hands
if
you’re not prepared.
When you drive over bumps, rocks, or other obstacles,
your wheels can leave the ground.
If this happens, even
with one or two wheels, you can’t control the vehicle as
well or at all.
Because you will be on an unpaved surface, it‘s
especially important to avoid sudden acceleration,
sudden turns or sudden braking.
In a way, off-road driving requires a different kind of
alertness from driving on paved roads and highways.
There are
no road signs, posted speed limits or signal
lights. You have
to use your own good judgment about
what
is safe and what isn’t.
Drinking and driving can be very dangerous
on any
road. And
this is certainly true for off-road driving. At
the very time you need special alertness and driving
skills,
your reflexes, perceptions and judgment can be
affected by even a
small amount of alcohol. You could
have a serious -- or even fatal -- accident if you drink
and drive
or ride with a driver who has been drinking.
See “Drunken Driving”
in the Index.
Driving on Off-Road Hills
Off-road driving often takes you up, down or across a
hill. Driving safely on hills requires good judgment and
an understanding
of what your vehicle can and can’t do.
There are some hiIls that simply can’t be driven,
no
matter how well built the vehicle.
I
Many hills are simply too steep for any vehicle. If
you drive up them, you will stall. If you drive
down them, you can’t control your speed.
If you
drive across them, you
will roll over. You could be
seriously injured or killed.
If you have any doubt
about the steepness, don’t drive the hill.
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