Braking in Emergencies
At some time, nearly every driver gets into a situation
that requires hard braking.
If you have anti-lock brakes, you can steer and brake at
the same time. However, if you do not have anti-lock
brakes, your rst reaction — to hit the brake pedal hard
and hold it down — may be the wrong thing to do.
Your wheels can stop rolling. Once they do, the vehicle
cannot 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 do not have anti-lock brakes, 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 brakes, it is different. SeeAnti-Lock Brake
System (ABS) on page 4-7.
In many emergencies, steering can help you more than
even the very best braking.
Limited-Slip Rear Axle
Your vehicle may have this feature. A limited-slip rear
axle can give you additional traction on snow, mud, ice,
sand or gravel. It works like a standard axle most of
the time, but when one of the rear wheels has no
traction and the other does, this feature will allow the
wheel with traction to move the vehicle.
4-9
Do not get too close to the vehicle you want to pass
while you are awaiting an opportunity. For one thing,
following too closely reduces your area of vision,
especially if you are following a larger vehicle. Also,
you will not have adequate space if the vehicle
ahead suddenly slows or stops. Keep back a
reasonable distance.
When it looks like a chance to pass is coming up,
start to accelerate but stay in the right lane and do
not get too close. Time your move so you will be
increasing speed as the time comes to move into the
other lane. If the way is clear to pass, you will have a
running start that more than makes up for the
distance you would lose by dropping back. And if
something happens to cause you to cancel your
pass, you need only slow down and drop back again
and wait for another opportunity.
If other vehicles are lined up to pass a slow vehicle,
wait your turn. But take care that someone is not
trying to pass you as you pull out to pass the slow
vehicle. Remember to glance over your shoulder and
check the blind spot.
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
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.
Do not overtake a slowly moving vehicle too rapidly.
Even though the brake lamps are not ashing, it may
be slowing down or starting to turn.
If you are being passed, make it easy for the
following driver to get ahead of you. Perhaps you can
ease a little to the right.
4-13
Loss of Control
Let us review what driving experts say about what
happens when the three control systems — brakes,
steering, and acceleration — do not have enough friction
where the tires meet the road to do what the driver has
asked.
In any emergency, do not 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 the braking skid, your wheels
are not 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.
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
will 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.
If you have the anti-lock braking system (ABS),
remember: It helps avoid only the braking skid. If you do
not have ABS, then in a braking skid, where the
wheels are no longer rolling, release enough pressure
on the brakes to get the wheels rolling again. This
restores steering control. Push the brake pedal down
steadily when you have to stop suddenly. As long as the
wheels are rolling, you will have steering control.
4-14
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired — by alcohol or drugs, with night vision
problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the glare
from headlamps behind you.
Since you cannot see as well, you may need to
slow down and keep more space between you
and other vehicles.
Slow down, especially on higher speed roads. Your
vehicle’s headlamps can light up only so much road
ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe place
and rest.
No one can see as well at night as in the daytime. But
as we get older these differences increase. A
50-year-old driver may require at least twice as much
light to see the same thing at night as a 20-year-old.What you do in the daytime can also affect your night
vision. For example, if you spend the day in bright
sunshine you are wise to wear sunglasses. Your eyes
will have less trouble adjusting to night. But if you
are driving, do not wear sunglasses at night. They may
cut down on glare from headlamps, but they also
make a lot of things invisible.
You can be temporarily blinded by approaching
headlamps. It can take a second or two, or even several
seconds, for your eyes to re-adjust to the dark. When
you are faced with severe glare, as from a driver
who does not lower the high beams, or a vehicle with
misaimed headlamps, slow down a little. Avoid
staring directly into the approaching headlamps.
Keep the windshield and all the glass on your vehicle
clean — inside and out. Glare at night is made
much worse by dirt on the glass. Even the inside of the
glass can build up a lm caused by dust. Dirty glass
makes lights dazzle and ash more than clean
glass would, making the pupils of your eyes contract
repeatedly.
Remember that the headlamps light up far less of a
roadway when you are in a turn or curve. Keep your eyes
moving; that way, it is easier to pick out dimly lighted
objects. Just as the headlamps should be checked
regularly for proper aim, so should your eyes be
examined regularly. Some drivers suffer from night
blindness — the inability to see in dim light — and are not
even aware of it.
4-15
Driving Through Deep Standing Water
Notice:If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage
your engine. Never drive through water that is
slightly lower than the underbody of your vehicle. If
you cannot avoid deep puddles or standing water,
drive through them very slowly.
Driving Through Flowing Water
{CAUTION:
Flowing or rushing water creates strong
forces. If you try to drive through owing
water, as you might at a low water crossing,
your vehicle can be carried away. As little as
six inches of owing water can carry away a
smaller vehicle. If this happens, you and other
vehicle occupants could drown. Do not ignore
police warning signs, and otherwise be very
cautious about trying to drive through owing
water.
Some Other Rainy Weather Tips
Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
Have good tires with proper tread depth. SeeTires
on page 5-44.
4-18
You can run the engine to keep warm, but be careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You cannot see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
4-27
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.
Cold In ation Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeIn ation - Tire Pressure on page 5-50.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the U.S.
Department of Transportation (DOT) motor vehicle
safety standards. The DOT code includes the Tire
Identi cation Number (TIN), an alphanumeric designator
which can also identify the tire manufacturer, production
plant, brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-29.GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-29.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-29.
Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward when
mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
Light Truck (LT-Metric) Tire:A tire used on light duty
trucks and some multipurpose passenger vehicles.
Load Index:An assigned number ranging from
1 to 279 that corresponds to the load carrying capacity
of a tire.
Maximum In ation Pressure:The maximum air
pressure to which a cold tire may be in ated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible in ation pressure for that tire.
Maximum Loaded Vehicle Weight:The sum of curb
weight; accessory weight; vehicle capacity weight;
and production options weight.
Normal Occupant Weight:The number of occupants a
vehicle is designed to seat multiplied by 150 lbs (68 kg).
SeeLoading Your Vehicle on page 4-29.
5-48
Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance. (This
applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signi cantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on speci ed government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
5-55